In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on Roche/Hitachi cobas c systems.
Colorimetric endpoint method
Sample and addition of R1
Addition of R2 and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Measuring range
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Lower limits of measurement
Limit of Blank, Limit of Detection and Limit of Quantitation
Serum/plasma
Limit of Blank | = 0.05 mmol/L (0.122 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Quantitation | = 0.10 mmol/L (0.243 mg/dL) |
Urine
Limit of Blank | = 0.28 mmol/L (0.68 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Limit of Quantitation | = 0.56 mmol/L (1.36 mg/dL) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a total error of 20 %. It has been determined using low concentration magnesium samples.
mmol/L
Serum/plasma: | |
Newborn: | 0.62‑0.91 mmol/L |
5 months‑6 years: | 0.70‑0.95 mmol/L |
6‑12 years: | 0.70‑0.86 mmol/L |
12‑20 years: | 0.70‑0.91 mmol/L |
Adults: | 0.66‑1.07 mmol/L |
60‑90 years: | 0.66‑0.99 mmol/L |
> 90 years: | 0.70‑0.95 mmol/L |
Urine (24 h): | 3.0‑5.0 mmol/d |
mg/dL
Serum/plasma: | |
Newborn: | 1.5‑2.2 mg/dL |
5 months‑6 years: | 1.7‑2.3 mg/dL |
6‑12 years: | 1.7‑2.1 mg/dL |
12‑20 years: | 1.7‑2.2 mg/dL |
Adults: | 1.6‑2.6 mg/dL |
60‑90 years: | 1.6‑2.4 mg/dL |
> 90 years: | 1.7‑2.3 mg/dL |
Urine (24 h): | 72.9‑121.5 mg/d |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL, 1.4 mval/L).
Serum/plasma
Icterus:
Hemolysis:
Hemolysis elevates results depending on the content of the analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.1 mg/dL, 3.4 mval/L).
Hemolysis:
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on Roche/Hitachi cobas c systems. All special wash programming necessary for avoiding carry‑over is available via the cobas link. The latest version of the carry‑over evasion list can be found with the NaOHD/SMS/SCCS Method Sheet for information. For further instructions refer to the operator’s manual.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
08058016 190 | Magnesium Gen.2 (690 tests) | System‑ID 2089 001 | Roche/Hitachi cobas c 503 |
Materials required (but not provided):
10759350 190 | Calibrator f.a.s. (12 x 3 mL) | Code 20401 | |
10759350 360 | Calibrator f.a.s. (12 x 3 mL, for USA) | Code 20401 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 20391 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 20391 | |
05947626 160 | PreciControl ClinChem Multi 1 (4 x 5 mL, for USA) | Code 20391 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 20392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 20392 | |
05947774 160 | PreciControl ClinChem Multi 2 (4 x 5 mL, for USA) | Code 20392 | |
08063494 190 | Diluent NaCl 9 % (123 mL) | System‑ID 2906 001 |
MG2: ACN 20890 (Serum/plasma)
MG2U: ACN 20891 (Urine)
Ready for use
Test definition | |||
Reporting time | 10 min | ||
Wavelength (sub/main) | 505/600 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 78 µL | – | |
R3 | 78 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.4 µL | – | – |
Decreased | 1.2 µL | – | – |
Increased | 2.4 µL | – | – |
Application for urine
Test definition | |||
Reporting time | 10 min | ||
Wavelength (sub/main) | 505/600 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 78 µL | - | |
R3 | 78 µL | - | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.4 µL | 20 µL | 90 µL |
Decreased | 2.4 µL | 10 µL | 100 µL |
Increased | 2.4 µL | 20 µL | 90 µL |
For further information about the assay test definitions refer to the application parameters setting screen of the corresponding analyzer and assay.
Shelf life at 15‑25 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 26 weeks |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | Automatic full calibration Full calibration |
Application for urine (ACN 20891)
Transfer of calibration from serum/plasma application (ACN 20890)
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against atomic absorption spectrometry.
For the USA, this method has been standardized against SRM 956.
Representative performance data on the analyzers are given below. These data represent the performance of the analytical procedure itself.
Results obtained in individual laboratories may differ due to heterogenous sample materials, aging of analyzer components and mixture of reagents running on the analyzer.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP05‑A3 requirements with repeatability (n = 84) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days).
The following results were obtained:
Serum/plasma
Repeatability | Mean | SD | CV |
PCCC1b) | 0.812 | 0.00352 | 0.4 |
PCCC2c) | 1.30 | 0.00546 | 0.4 |
Human serum 1 | 0.258 | 0.00386 | 1.5 |
Human serum 2 | 0.624 | 0.00384 | 0.6 |
Human serum 3 | 0.986 | 0.00346 | 0.4 |
Human serum 4 | 1.36 | 0.00567 | 0.4 |
Human serum 5 | 1.74 | 0.00577 | 0.3 |
Intermediate precision | Mean | SD | CV |
PCCC1 FREFPreciControl ClinChem Multi 1 | 0.812 | 0.00940 | 1.2 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 1.30 | 0.0127 | 1.0 |
Human serum 1 | 0.258 | 0.00648 | 2.5 |
Human serum 2 | 0.624 | 0.00699 | 1.1 |
Human serum 3 | 0.986 | 0.00651 | 0.7 |
Human serum 4 | 1.37 | 0.00812 | 0.6 |
Human serum 5 | 1.74 | 0.00896 | 0.5 |
Urine
Repeatability | Mean | SD | CV |
Control 1d) | 1.73 | 0.0231 | 1.3 |
Control 2d) | 3.67 | 0.0252 | 0.7 |
Human urine 1 | 1.50 | 0.0243 | 1.6 |
Human urine 2 | 2.90 | 0.0238 | 0.8 |
Human urine 3 | 4.08 | 0.0262 | 0.6 |
Human urine 4 | 5.30 | 0.0334 | 0.6 |
Human urine 5 | 9.02 | 0.0425 | 0.5 |
Intermediate precision | Mean | SD | CV |
Control 1 FREFcommercially available control material | 1.72 | 0.0302 | 1.8 |
Control 2 FREFcommercially available control material | 3.67 | 0.0313 | 0.9 |
Human urine 1 | 1.50 | 0.0288 | 1.9 |
Human urine 2 | 2.89 | 0.0336 | 1.2 |
Human urine 3 | 4.08 | 0.0298 | 0.7 |
Human urine 4 | 5.27 | 0.0424 | 0.8 |
Human urine 5 | 9.02 | 0.0609 | 0.7 |
Magnesium values for human serum, plasma and urine samples obtained on a Roche/Hitachi cobas c 503 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi cobas c 501 analyzer (x).
Serum/plasma
Sample size (n) = 97
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.013x - 0.00748 mmol/L | y = 1.011x - 0.00537 mmol/L |
τ = 0.984 | r = 1.000 |
The sample concentrations were between 0.100 and 1.96 mmol/L. |
Urine
Sample size (n) = 62
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.963x - 0.0757 mmol/L | y = 0.973x - 0.114 mmol/L |
τ = 0.974 | r = 0.999 |
The sample concentrations were between 0.670 and 11.0 mmol/L. |
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP‑magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRIS FREFTRIS = Tris(hydroxymethyl)‑aminomethane /6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
R3 | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
R1 is in position B and R3 is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590, USA: 1-800-428-2336
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
Serum/plasma: | PreciControl ClinChem Multi 1, PreciControl ClinChem Multi 2 |
Urine: | Quantitative urine controls are recommended for routine quality control. |
The control intervals and limits should be adapted to each laboratory’s individual requirements.
It is recommended to perform quality control always after lot calibration and subsequently at least every 26 weeks.
Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li‑heparin plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesium ammonium phosphate. Collect urine samples in metal‑free container.
Stability in urine: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 3 days at 15‑25 °C |
3 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on
Colorimetric endpoint method
Sample and addition of R1
Addition of R3 and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Measuring range
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. For samples with higher concentrations, the rerun function decreases the sample volume by a factor of 2. The results are automatically multiplied by this factor.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Lower limits of measurement
Limit of Blank, Limit of Detection and Limit of Quantitation
Serum/plasma
Limit of Blank | = 0.05 mmol/L (0.122 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Quantitation | = 0.10 mmol/L (0.243 mg/dL) |
Urine
Limit of Blank | = 0.28 mmol/L (0.68 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Limit of Quantitation | = 0.56 mmol/L (1.36 mg/dL) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a total error of 20 %. It has been determined using low concentration magnesium samples.
mmol/L
Serum/plasma: | |
Newborn: | 0.62‑0.91 mmol/L |
5 months‑6 years: | 0.70‑0.95 mmol/L |
6‑12 years: | 0.70‑0.86 mmol/L |
12‑20 years: | 0.70‑0.91 mmol/L |
Adults: | 0.66‑1.07 mmol/L |
60‑90 years: | 0.66‑0.99 mmol/L |
> 90 years: | 0.70‑0.95 mmol/L |
Urine (24 h): | 3.0‑5.0 mmol/d |
mg/dL
Serum/plasma: | |
Newborn: | 1.5‑2.2 mg/dL |
5 months‑6 years: | 1.7‑2.3 mg/dL |
6‑12 years: | 1.7‑2.1 mg/dL |
12‑20 years: | 1.7‑2.2 mg/dL |
Adults: | 1.6‑2.6 mg/dL |
60‑90 years: | 1.6‑2.4 mg/dL |
> 90 years: | 1.7‑2.3 mg/dL |
Urine (24 h): | 72.9‑121.5 mg/d |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Serum/plasma
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL, 1.4 mval/L).
Icterus:
Hemolysis:
Hemolysis elevates results depending on the content of the analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.1 mg/dL, 3.4 mval/L).
Hemolysis: No significant interference up to an H index of 1000 (approximate hemoglobin concentration of 621 µmol/L or 1000 mg/dL).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on cobas c systems. All special wash programming necessary for avoiding carry-over is available via the cobas link. The latest version of the carry-over evasion list can be found with the NaOHD/SMS/SCCS Method Sheet. For further instructions, refer to the operator’s manual.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
08058016190 | Magnesium Gen.2 (690 tests) | System‑ID 2089 001 | cobas c 303, cobas c 503 |
Materials required (but not provided):
10759350360 | Calibrator f.a.s. (12 x 3 mL) | Code 20401 | |
05947626160 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 20391 | |
05947774160 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 20392 | |
08063494190 | Diluent NaCl 9 % (123 mL) | System‑ID 2906 001 |
MG2: ACN 20890 (Serum/plasma)
MG2U: ACN 20891 (Urine)
Ready for use
Test definition | |||
Reporting time | 10 min | ||
Wavelength (sub/main) | 505/600 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 78 µL | – | |
R3 | 78 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.4 µL | – | – |
Decreased | 1.2 µL | – | – |
Increased | 2.4 µL | – | – |
Application for urine
Test definition | |||
Reporting time | 10 min | ||
Wavelength (sub/main) | 505/600 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 78 µL | - | |
R3 | 78 µL | - | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.4 µL | 20 µL | 90 µL |
Decreased | 2.4 µL | 10 µL | 100 µL |
Increased | 2.4 µL | 20 µL | 90 µL |
For further information about the assay test definitions refer to the application parameters setting screen of the corresponding analyzer and assay.
Shelf life at 15‑25 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 26 weeks |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | Automatic full calibration Full calibration |
Application for urine (ACN 20891)
Transfer of calibration from serum/plasma application (ACN 20890)
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Representative performance data on the analyzers are given below. These data represent the performance of the analytical procedure itself.
Results obtained in individual laboratories may differ due to heterogenous sample materials, aging of analyzer components and mixture of reagents running on the analyzer.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP05‑A3 requirements with repeatability (n = 84) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days).
Results for repeatability and intermediate precision were obtained on the cobas c 503 analyzer.
Serum/plasma
Repeatability | Mean | SD | CV |
PCCC1b) | 0.812 (1.97) | 0.00352 (0.00855) | 0.4 |
PCCC2c) | 1.30 (3.16) | 0.00546 (0.0133) | 0.4 |
Human serum 1 | 0.258 (0.627) | 0.00386 (0.00938) | 1.5 |
Human serum 2 | 0.624 (1.52) | 0.00384 (0.00933) | 0.6 |
Human serum 3 | 0.986 (2.40) | 0.00346 (0.00841) | 0.4 |
Human serum 4 | 1.36 (3.30) | 0.00567 (0.0138) | 0.4 |
Human serum 5 | 1.74 (4.23) | 0.00577 (0.0140) | 0.3 |
Intermediate precision | Mean | SD | CV |
PCCC1 FREFPreciControl ClinChem Multi 1 | 0.812 (1.97) | 0.00940 (0.0228) | 1.2 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 1.30 (3.16) | 0.0127 (0.0309) | 1.0 |
Human serum 1 | 0.258 (0.627) | 0.00648 (0.0157) | 2.5 |
Human serum 2 | 0.624 (1.52) | 0.00699 (0.0170) | 1.1 |
Human serum 3 | 0.986 (2.40) | 0.00651 (0.0158) | 0.7 |
Human serum 4 | 1.37 (3.33) | 0.00812 (0.0197) | 0.6 |
Human serum 5 | 1.74 (4.23) | 0.00896 (0.0218) | 0.5 |
Urine
Repeatability | Mean | SD | CV |
Control 1d) | 1.73 (4.20) | 0.0231 (0.0561) | 1.3 |
Control 2d) | 3.67 (8.92) | 0.0252 (0.0612) | 0.7 |
Human urine 1 | 1.50 (3.65) | 0.0243 (0.0590) | 1.6 |
Human urine 2 | 2.90 (7.05) | 0.0238 (0.0578) | 0.8 |
Human urine 3 | 4.08 (9.91) | 0.0262 (0.0637) | 0.6 |
Human urine 4 | 5.30 (12.9) | 0.0334 (0.0812) | 0.6 |
Human urine 5 | 9.02 (21.9) | 0.0425 (0.103) | 0.5 |
Intermediate precision | Mean | SD | CV |
Control 1 FREFcommercially available control material | 1.72 (4.18) | 0.0302 (0.0734) | 1.8 |
Control 2 FREFcommercially available control material | 3.67 (8.92) | 0.0313 (0.0761) | 0.9 |
Human urine 1 | 1.50 (3.65) | 0.0288 (0.0700) | 1.9 |
Human urine 2 | 2.89 (7.02) | 0.0336 (0.0816) | 1.2 |
Human urine 3 | 4.08 (9.91) | 0.0298 (0.0724) | 0.7 |
Human urine 4 | 5.27 (12.8) | 0.0424 (0.103) | 0.8 |
Human urine 5 | 9.02 (21.9) | 0.0609 (0.148) | 0.7 |
Magnesium values for human serum, plasma and urine samples obtained on a cobas c 503 analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Serum/plasma
Sample size (n) = 97
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.013x - 0.00748 mmol/L | y = 1.011x - 0.00537 mmol/L |
τ = 0.984 | r = 1.000 |
The sample concentrations were between 0.100 and 1.96 mmol/L (0.243 and 4.76 mg/dL). |
Urine
Sample size (n) = 62
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.963x - 0.0757 mmol/L | y = 0.973x - 0.114 mmol/L |
τ = 0.974 | r = 0.999 |
The sample concentrations were between 0.670 and 11.0 mmol/L (1.63 and 26.7 mg/dL). |
Magnesium values for human serum, plasma and urine samples obtained on a cobas c 303 analyzer (y) were compared with those determined using the corresponding reagent on a cobas c 501 analyzer (x).
Serum/plasma
Sample size (n) = 72
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.011x + 0.000944 mmol/L | y = 1.012x + 0.000238 mmol/L |
τ = 0.979 | r = 1.000 |
The sample concentrations were between 0.140 and 1.94 mmol/L (0.340 and 4.71 mg/dL). |
Urine
Sample size (n) = 67
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.007x + 0.00729 mmol/L | y = 1.008x + 0.00459 mmol/L |
τ = 0.984 | r = 1.000 |
The sample concentrations were between 0.610 and 10.7 mmol/L (1.48 and 26.0 mg/dL). |
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP‑magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRIS FREFTRIS = Tris(hydroxymethyl)‑aminomethane /6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
R3 | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
R1 is in position B and R3 is in position C.
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: 1-800-428-2336
For quality control, use control materials as listed in the \"Order information\" section.
In addition, other suitable control material can be used.
Serum/plasma: | PreciControl ClinChem Multi 1, PreciControl ClinChem Multi 2 |
Urine: | Quantitative urine controls are recommended for routine quality control. |
The control intervals and limits should be adapted to each laboratory’s individual requirements.
It is recommended to perform quality control always after lot calibration and subsequently at least every 26 weeks.
Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li‑heparin plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C | |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesium ammonium phosphate. Collect urine samples in metal‑free container.
Stability in urine: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 3 days at 15‑25 °C |
3 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C | |
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on Roche/Hitachi cobas c systems.
Colorimetric endpoint method
Sample and addition of R1
Addition of R2 and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Measuring range
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Lower limits of measurement
Limit of Blank, Limit of Detection and Limit of Quantitation
Serum/plasma
Limit of Blank | = 0.05 mmol/L (0.122 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Quantitation | = 0.10 mmol/L (0.243 mg/dL) |
Urine
Limit of Blank | = 0.28 mmol/L (0.68 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Limit of Quantitation | = 0.56 mmol/L (1.36 mg/dL) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a total error of 20 %. It has been determined using low concentration magnesium samples.
mmol/L
Serum/plasma: | |
Newborn: | 0.62‑0.91 mmol/L |
5 months‑6 years: | 0.70‑0.95 mmol/L |
6‑12 years: | 0.70‑0.86 mmol/L |
12‑20 years: | 0.70‑0.91 mmol/L |
Adults: | 0.66‑1.07 mmol/L |
60‑90 years: | 0.66‑0.99 mmol/L |
> 90 years: | 0.70‑0.95 mmol/L |
Urine (24 h): | 3.0‑5.0 mmol/d |
mg/dL
Serum/plasma: | |
Newborn: | 1.5‑2.2 mg/dL |
5 months‑6 years: | 1.7‑2.3 mg/dL |
6‑12 years: | 1.7‑2.1 mg/dL |
12‑20 years: | 1.7‑2.2 mg/dL |
Adults: | 1.6‑2.6 mg/dL |
60‑90 years: | 1.6‑2.4 mg/dL |
> 90 years: | 1.7‑2.3 mg/dL |
Urine (24 h): | 72.9‑121.5 mg/d |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL, 1.4 mval/L).
Serum/plasma
Icterus:
Hemolysis:
Hemolysis elevates results depending on the content of the analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.1 mg/dL, 3.4 mval/L).
Hemolysis: No significant interference up to an H index of 1000 (approximate hemoglobin concentration of 621 µmol/L or 1000 mg/dL).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on
|
| Analyzer(s) on which cobas c pack(s) can be used | |
08058016190 | Magnesium Gen.2 (690 tests) | System‑ID 2089 001 | cobas c 303, cobas c 503 |
Materials required (but not provided):
10759350190 | Calibrator f.a.s. (12 x 3 mL) | Code 20401 | |
05117003190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 20391 | |
05947626190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 20391 | |
05117216190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 20392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 20392 | |
08063494190 | Diluent NaCl 9 % (123 mL) | System‑ID 2906 001 |
MG2: ACN 20890 (Serum/plasma)
MG2U: ACN 20891 (Urine)
Ready for use
Test definition | |||
Reporting time | 10 min | ||
Wavelength (sub/main) | 505/600 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 78 µL | – | |
R3 | 78 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.4 µL | – | – |
Decreased | 1.2 µL | – | – |
Increased | 2.4 µL | – | – |
Application for urine
Test definition | |||
Reporting time | 10 min | ||
Wavelength (sub/main) | 505/600 nm | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 78 µL | - | |
R3 | 78 µL | - | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 2.4 µL | 20 µL | 90 µL |
Decreased | 2.4 µL | 10 µL | 100 µL |
Increased | 2.4 µL | 20 µL | 90 µL |
For further information about the assay test definitions refer to the application parameters setting screen of the corresponding analyzer and assay.
Shelf life at 15‑25 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 26 weeks |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | Automatic full calibration Full calibration |
Application for urine (ACN 20891)
Transfer of calibration from serum/plasma application (ACN 20890)
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against atomic absorption spectrometry.
For the USA, this method has been standardized against SRM 956.
Representative performance data on the analyzers are given below. These data represent the performance of the analytical procedure itself.
Results obtained in individual laboratories may differ due to heterogenous sample materials, aging of analyzer components and mixture of reagents running on the analyzer.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP05‑A3 requirements with repeatability (n = 84) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days).
Serum/plasma
Repeatability | Mean | SD | CV |
PCCC1b) | 0.812 | 0.00352 | 0.4 |
PCCC2c) | 1.30 | 0.00546 | 0.4 |
Human serum 1 | 0.258 | 0.00386 | 1.5 |
Human serum 2 | 0.624 | 0.00384 | 0.6 |
Human serum 3 | 0.986 | 0.00346 | 0.4 |
Human serum 4 | 1.36 | 0.00567 | 0.4 |
Human serum 5 | 1.74 | 0.00577 | 0.3 |
Intermediate precision | Mean | SD | CV |
PCCC1 FREFPreciControl ClinChem Multi 1 | 0.812 | 0.00940 | 1.2 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 1.30 | 0.0127 | 1.0 |
Human serum 1 | 0.258 | 0.00648 | 2.5 |
Human serum 2 | 0.624 | 0.00699 | 1.1 |
Human serum 3 | 0.986 | 0.00651 | 0.7 |
Human serum 4 | 1.37 | 0.00812 | 0.6 |
Human serum 5 | 1.74 | 0.00896 | 0.5 |
Urine
Repeatability | Mean | SD | CV |
Control 1d) | 1.73 | 0.0231 | 1.3 |
Control 2d) | 3.67 | 0.0252 | 0.7 |
Human urine 1 | 1.50 | 0.0243 | 1.6 |
Human urine 2 | 2.90 | 0.0238 | 0.8 |
Human urine 3 | 4.08 | 0.0262 | 0.6 |
Human urine 4 | 5.30 | 0.0334 | 0.6 |
Human urine 5 | 9.02 | 0.0425 | 0.5 |
Intermediate precision | Mean | SD | CV |
Control 1 FREFcommercially available control material | 1.72 | 0.0302 | 1.8 |
Control 2 FREFcommercially available control material | 3.67 | 0.0313 | 0.9 |
Human urine 1 | 1.50 | 0.0288 | 1.9 |
Human urine 2 | 2.89 | 0.0336 | 1.2 |
Human urine 3 | 4.08 | 0.0298 | 0.7 |
Human urine 4 | 5.27 | 0.0424 | 0.8 |
Human urine 5 | 9.02 | 0.0609 | 0.7 |
Magnesium values for human serum, plasma and urine samples obtained on a
Serum/plasma
Sample size (n) = 97
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.013x - 0.00748 mmol/L | y = 1.011x - 0.00537 mmol/L |
τ = 0.984 | r = 1.000 |
The sample concentrations were between 0.100 and 1.96 mmol/L. |
Urine
Sample size (n) = 62
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.963x - 0.0757 mmol/L | y = 0.973x - 0.114 mmol/L |
τ = 0.974 | r = 0.999 |
The sample concentrations were between 0.670 and 11.0 mmol/L. |
Serum/plasma
Sample size (n) = 72
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.011x + 0.000944 mmol/L | y = 1.012x + 0.000238 mmol/L |
τ = 0.979 | r = 1.000 |
The sample concentrations were between 0.140 and 1.94 mmol/L. |
Urine
Sample size (n) = 67
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.007x + 0.00729 mmol/L | y = 1.008x + 0.00459 mmol/L |
τ = 0.984 | r = 1.000 |
The sample concentrations were between 0.610 and 10.7 mmol/L. |
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP‑magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRIS FREFTRIS = Tris(hydroxymethyl)‑aminomethane /6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
R3 | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
R1 is in position B and R3 is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
Serum/plasma: | PreciControl ClinChem Multi 1, PreciControl ClinChem Multi 2 |
Urine: | Quantitative urine controls are recommended for routine quality control. |
The control intervals and limits should be adapted to each laboratory’s individual requirements.
It is recommended to perform quality control always after lot calibration and subsequently at least every 26 weeks.
Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li‑heparin plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesium ammonium phosphate. Collect urine samples in metal‑free container.
Stability in urine: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 3 days at 15‑25 °C |
3 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on Roche/Hitachi cobas c systems.
Colorimetric endpoint method
Sample and addition of R1
Addition of R3 and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Measuring range
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Lower limits of measurement
Limit of Blank and Limit of Detection
Serum/plasma
Limit of Blank | = 0.05 mmol/L (0.122 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Values below the Limit of Detection (< 0.10 mmol/L) will not be flagged by the instrument.
Urine
Limit of Blank | = 0.28 mmol/L (0.680 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Values below the Limit of Detection (< 0.56 mmol/L) will not be flagged by the instrument.
The Limit of Blank and Limit of Detection were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
Serum/plasma: | ||
Newborn: | 0.62‑0.91 mmol/L | (1.5‑2.2 mg/dL) |
5 months‑6 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
6‑12 years: | 0.70‑0.86 mmol/L | (1.7‑2.1 mg/dL) |
12‑20 years: | 0.70‑0.91 mmol/L | (1.7‑2.2 mg/dL) |
Adults: | 0.66‑1.07 mmol/L | (1.6‑2.6 mg/dL) |
60‑90 years: | 0.66‑0.99 mmol/L | (1.6‑2.4 mg/dL) |
> 90 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
Urine (24 h): | ||
3.0‑5.0 mmol/d | (72.9‑121.5 mg/d) |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL, 1.4 mval/L).
Serum/plasma
Icterus:
Hemolysis:
Hemolysis elevates results depending on the content of the analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.1 mg/dL, 3.4 mval/L).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on Roche/Hitachi cobas c systems. All special wash programming necessary for avoiding carry‑over is available via the cobas link, manual input is required in certain cases. The latest version of the carry‑over evasion list can be found with the NaOHD/SMS/SmpCln1+2/SCCS Method Sheet and for further instructions refer to the operator’s manual.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
Magnesium Gen.2 (200 tests) | System‑ID 01 7486 3 | Roche/Hitachi cobas c 701/702 | |
06407358 214* | Magnesium Gen.2 (200 tests) | System‑ID 01 7486 3 | Roche/Hitachi cobas c 701/702 |
10759350 190 | Calibrator f.a.s. (12 x 3 mL) | Code 401 | |
10759350 360 | Calibrator f.a.s. (12 x 3 mL, for USA) | Code 401 | |
12149435 122 | Precinorm U plus (10 x 3 mL) | Code 300 | |
12149435 160 | Precinorm U plus (10 x 3 mL, for USA) | Code 300 | |
12149443 122 | Precipath U plus (10 x 3 mL) | Code 301 | |
12149443 160 | Precipath U plus (10 x 3 mL, for USA) | Code 301 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05947626 160 | PreciControl ClinChem Multi 1 (4 x 5 mL, for USA) | Code 391 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05947774 160 | PreciControl ClinChem Multi 2 (4 x 5 mL, for USA) | Code 392 | |
05172152 190 | Diluent NaCl 9 % (119 mL) | System‑ID 08 6869 3 |
MG‑2: | ACN 8701 (serum and plasma) |
MGU‑2: | ACN 8704 (urine) |
SMG2: | ACN 8688 (STAT, serum and plasma, reaction time: 4) |
SMG2U: | ACN 8689 (STAT, urine, reaction time: 4) |
Ready for use
cobas c 701/702 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 18‑27 (STAT 4 / 6‑15) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R3 (STAT R2) | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (H2O) | ||
Normal | 3 µL | – | – |
Decreased | 1.5 µL | – | – |
Increased | 6 µL | – | – |
Application for urine
cobas c 701/702 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 18‑27 (STAT 4 / 6‑15) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R3 (STAT R2) | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 6 µL | 14 µL | 140 µL |
Decreased | 3 µL | 14 µL | 140 µL |
Increased | 12 µL | 14 µL | 140 µL |
MG2 | |
Shelf life at 15‑25 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 10 days |
On‑board on the Reagent Manager | 24 hours |
Diluent NaCl 9 % | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 4 weeks |
On‑board on the Reagent Manager | 24 hours |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against atomic absorption spectrometry.
For the USA, this method has been standardized against SRM 956.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (3 aliquots per run, 1 run per day, 10 days).
The following results were obtained:
Serum/plasma
MG‑2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.987 (2.40) | 0.005 (0.01) | 0.5 |
Precipath U | 1.81 (4.40) | 0.01 (0.02) | 0.5 |
Human serum A | 0.636 (1.55) | 0.005 (0.01) | 0.8 |
Human serum B | 0.982 (2.39) | 0.008 (0.02) | 0.8 |
Human serum C | 1.88 (4.57) | 0.01 (0.02) | 0.8 |
SMG2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.972 (2.36) | 0.005 (0.01) | 0.5 |
Precipath U | 1.79 (4.35) | 0.01 (0.02) | 0.3 |
Human serum A | 0.624 (1.52) | 0.005 (0.01) | 0.8 |
Human serum B | 0.976 (2.37) | 0.006 (0.01) | 0.6 |
Human serum C | 1.86 (4.52) | 0.01 (0.02) | 0.5 |
MG‑2/SMG2
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.974 (2.37) | 0.013 (0.03) | 1.3 |
Precipath U | 1.79 (4.35) | 0.02 (0.05) | 1.4 |
Human serum D | 0.626 (1.52) | 0.011 (0.03) | 1.7 |
Human serum E | 0.969 (2.35) | 0.013 (0.03) | 1.4 |
Human serum F | 1.95 (4.74) | 0.03 (0.07) | 1.5 |
Urine
MGU‑2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 2.02 (4.91) | 0.02 (0.05) | 1.1 |
Control level 2 | 4.83 (11.7) | 0.02 (0.05) | 0.4 |
Human urine A | 1.43 (3.47) | 0.03 (0.07) | 2.3 |
Human urine B | 3.07 (7.46) | 0.02 (0.05) | 0.6 |
Human urine C | 8.29 (20.1) | 0.04 (0.10) | 0.5 |
SMG2U
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 2.01 (4.88) | 0.03 (0.07) | 1.3 |
Control level 2 | 4.78 (11.6) | 0.03 (0.07) | 0.6 |
Human urine A | 1.41 (3.43) | 0.02 (0.05) | 1.3 |
Human urine B | 3.03 (7.36) | 0.02 (0.05) | 0.7 |
Human urine C | 8.23 (20.0) | 0.05 (0.12) | 0.6 |
MGU‑2/SMG2U
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 13.8 (33.5) | 0.2 (0.5) | 1.7 |
Control level 2 | 3.21 (7.80) | 0.12 (0.29) | 3.8 |
Human urine 1 | 2.89 (7.02) | 0.13 (0.32) | 4.6 |
Results for intermediate precision in urine were obtained on the Roche/Hitachi MODULAR P system.
Magnesium values for human serum/plasma and urine samples obtained on a Roche/Hitachi cobas c 701 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi 917 analyzer (x).
Serum/plasma
MG‑2
Sample size (n) = 87
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.027x - 0.02 mmol/L | y = 1.029x - 0.021 mmol/L |
τ = 0.958 | r = 0.998 |
The sample concentrations were between 0.560 and 1.94 mmol/L (1.36 and 4.71 mg/dL). |
SMG2
Sample size (n) = 86
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.012x - 0.010 mmol/L | y = 1.016x - 0.014 mmol/L |
τ = 0.959 | r = 0.998 |
The sample concentrations were between 0.560 and 1.94 mmol/L (1.36 and 4.71 mg/dL). |
Urine
MGU‑2
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.013x + 0.016 mmol/L | |
τ = 0.990 | r = 1.000 |
The sample concentrations were between 0.600 and 10.3 mmol/L (1.46 |
SMG2U
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.000x + 0.020 mmol/L | y = 1.002x + |
τ = 0.989 | r = 1.000 |
The sample concentrations were between |
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP‑magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRISa/6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
R3 | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
a) TRIS = Tris(hydroxymethyl)‑aminomethane |
R1 is in position B and R3 (STAT R2) is in position C.
For in vitro diagnostic use.
Exercise the normal precautions required for handling all laboratory reagents.
Disposal of all waste material should be in accordance with local guidelines.
Safety data sheet available for professional user on request.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590, USA: 1-800-428-2336
Serum/plasma
For quality control, use control materials as listed in the \"Order information\" section.
In addition, other suitable control material can be used.
Urine
Quantitative urine controls are recommended for routine quality control.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum.
Plasma: Li‑heparin plasma.
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFWHO Publication: Use of anticoagulants in diagnostic laboratory investigations, WHO/DIL/LAB/99.1 Rev.2:Jan 2002. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesium ammonium phosphate. Collect urine samples in metal‑free container.
Stability in urine: LREFWHO Publication: Use of anticoagulants in diagnostic laboratory investigations, WHO/DIL/LAB/99.1 Rev.2:Jan 2002. | 3 days at 15‑25 °C |
3 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on Roche/Hitachi cobas c systems.
Colorimetric endpoint method
Sample and addition of R1
Addition of R3 and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Measuring range
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Lower limits of measurement
Limit of Blank and Limit of Detection
Serum/plasma
Limit of Blank | = 0.05 mmol/L (0.122 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Values below the Limit of Detection (< 0.10 mmol/L) will not be flagged by the instrument.
Urine
Limit of Blank | = 0.28 mmol/L (0.680 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Values below the Limit of Detection (< 0.56 mmol/L) will not be flagged by the instrument.
The Limit of Blank and Limit of Detection were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
Serum/plasma: | ||
Newborn: | 0.62‑0.91 mmol/L | (1.5‑2.2 mg/dL) |
5 months‑6 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
6‑12 years: | 0.70‑0.86 mmol/L | (1.7‑2.1 mg/dL) |
12‑20 years: | 0.70‑0.91 mmol/L | (1.7‑2.2 mg/dL) |
Adults: | 0.66‑1.07 mmol/L | (1.6‑2.6 mg/dL) |
60‑90 years: | 0.66‑0.99 mmol/L | (1.6‑2.4 mg/dL) |
> 90 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
Urine (24 h): | ||
3.0‑5.0 mmol/d | (72.9‑121.5 mg/d) |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL, 1.4 mval/L).
Serum/plasma
Icterus:
Hemolysis:
Hemolysis elevates results depending on the content of the analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.1 mg/dL, 3.4 mval/L).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on Roche/Hitachi cobas c systems. All special wash programming necessary for avoiding carry‑over is available via the cobas link, manual input is required in certain cases. The latest version of the carry‑over evasion list can be found with the NaOHD/SMS/SmpCln1+2/SCCS Method Sheet and for further instructions refer to the operator’s manual.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
06407358 190* | Magnesium Gen.2 (200 tests) | System‑ID 01 7486 3 | Roche/Hitachi cobas c 701/702 |
06407358 214* | Magnesium Gen.2 (200 tests) | System‑ID 01 7486 3 | Roche/Hitachi cobas c 701/702 |
Materials required (but not provided):
10759350 190 | Calibrator f.a.s. (12 x 3 mL) | Code 401 | |
10759350 360 | Calibrator f.a.s. (12 x 3 mL, for USA) | Code 401 | |
12149435 122 | Precinorm U plus (10 x 3 mL) | Code 300 | |
12149435 160 | Precinorm U plus (10 x 3 mL, for USA) | Code 300 | |
12149443 122 | Precipath U plus (10 x 3 mL) | Code 301 | |
12149443 160 | Precipath U plus (10 x 3 mL, for USA) | Code 301 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05947626 160 | PreciControl ClinChem Multi 1 (4 x 5 mL, for USA) | Code 391 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05947774 160 | PreciControl ClinChem Multi 2 (4 x 5 mL, for USA) | Code 392 | |
05172152 190 | Diluent NaCl 9 % (119 mL) | System‑ID 08 6869 3 |
* Some kits shown may not be available in all countries.
MG‑2: | ACN 8701 (serum and plasma) |
MGU‑2: | ACN 8704 (urine) |
SMG2: | ACN 8688 (STAT, serum and plasma, reaction time: 4) |
SMG2U: | ACN 8689 (STAT, urine, reaction time: 4) |
Ready for use
cobas c 701/702 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 18‑27 (STAT 4 / 6‑15) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R3 (STAT R2) | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (H2O) | ||
Normal | 3 µL | – | – |
Decreased | 1.5 µL | – | – |
Increased | 6 µL | – | – |
Application for urine
cobas c 701/702 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 18‑27 (STAT 4 / 6‑15) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R3 (STAT R2) | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 6 µL | 14 µL | 140 µL |
Decreased | 3 µL | 14 µL | 140 µL |
Increased | 12 µL | 14 µL | 140 µL |
MG2 | |
Shelf life at 15‑25 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 10 days |
On‑board on the Reagent Manager | 24 hours |
Diluent NaCl 9 % | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 4 weeks |
On‑board on the Reagent Manager | 24 hours |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against atomic absorption spectrometry.
For the USA, this method has been standardized against SRM 956.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (3 aliquots per run, 1 run per day, 10 days).
The following results were obtained:
Serum/plasma
MG‑2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.987 (2.40) | 0.005 (0.01) | 0.5 |
Precipath U | 1.81 (4.40) | 0.01 (0.02) | 0.5 |
Human serum A | 0.636 (1.55) | 0.005 (0.01) | 0.8 |
Human serum B | 0.982 (2.39) | 0.008 (0.02) | 0.8 |
Human serum C | 1.88 (4.57) | 0.01 (0.02) | 0.8 |
SMG2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.972 (2.36) | 0.005 (0.01) | 0.5 |
Precipath U | 1.79 (4.35) | 0.01 (0.02) | 0.3 |
Human serum A | 0.624 (1.52) | 0.005 (0.01) | 0.8 |
Human serum B | 0.976 (2.37) | 0.006 (0.01) | 0.6 |
Human serum C | 1.86 (4.52) | 0.01 (0.02) | 0.5 |
MG‑2/SMG2
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.974 (2.37) | 0.013 (0.03) | 1.3 |
Precipath U | 1.79 (4.35) | 0.02 (0.05) | 1.4 |
Human serum D | 0.626 (1.52) | 0.011 (0.03) | 1.7 |
Human serum E | 0.969 (2.35) | 0.013 (0.03) | 1.4 |
Human serum F | 1.95 (4.74) | 0.03 (0.07) | 1.5 |
Urine
MGU‑2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 2.02 (4.91) | 0.02 (0.05) | 1.1 |
Control level 2 | 4.83 (11.7) | 0.02 (0.05) | 0.4 |
Human urine A | 1.43 (3.47) | 0.03 (0.07) | 2.3 |
Human urine B | 3.07 (7.46) | 0.02 (0.05) | 0.6 |
Human urine C | 8.29 (20.1) | 0.04 (0.10) | 0.5 |
SMG2U
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 2.01 (4.88) | 0.03 (0.07) | 1.3 |
Control level 2 | 4.78 (11.6) | 0.03 (0.07) | 0.6 |
Human urine A | 1.41 (3.43) | 0.02 (0.05) | 1.3 |
Human urine B | 3.03 (7.36) | 0.02 (0.05) | 0.7 |
Human urine C | 8.23 (20.0) | 0.05 (0.12) | 0.6 |
MGU‑2/SMG2U
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 13.8 (33.5) | 0.2 (0.5) | 1.7 |
Control level 2 | 3.21 (7.80) | 0.12 (0.29) | 3.8 |
Human urine 1 | 2.89 (7.02) | 0.13 (0.32) | 4.6 |
Results for intermediate precision in urine were obtained on the Roche/Hitachi MODULAR P system.
Magnesium values for human serum/plasma and urine samples obtained on a Roche/Hitachi cobas c 701 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi 917 analyzer (x).
Serum/plasma
MG‑2
Sample size (n) = 87
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.027x - 0.02 mmol/L | y = 1.029x - 0.021 mmol/L |
τ = 0.958 | r = 0.998 |
The sample concentrations were between 0.560 and 1.94 mmol/L (1.36 and 4.71 mg/dL). |
SMG2
Sample size (n) = 86
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.012x - 0.010 mmol/L | y = 1.016x - 0.014 mmol/L |
τ = 0.959 | r = 0.998 |
The sample concentrations were between 0.560 and 1.94 mmol/L (1.36 and 4.71 mg/dL). |
Urine
MGU‑2
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.013x + 0.016 mmol/L | |
τ = 0.990 | r = 1.000 |
The sample concentrations were between 0.600 and 10.3 mmol/L (1.46 |
SMG2U
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.000x + 0.020 mmol/L | y = 1.002x + |
τ = 0.989 | r = 1.000 |
The sample concentrations were between |
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP‑magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRISa/6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
R3 | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
a) TRIS = Tris(hydroxymethyl)‑aminomethane |
R1 is in position B and R3 (STAT R2) is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590, USA: 1-800-428-2336
Serum/plasma
For quality control, use control materials as listed in the \"Order information\" section.
In addition, other suitable control material can be used.
Urine
Quantitative urine controls are recommended for routine quality control.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum.
Plasma: Li‑heparin plasma.
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFWHO Publication: Use of anticoagulants in diagnostic laboratory investigations, WHO/DIL/LAB/99.1 Rev.2:Jan 2002. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesium ammonium phosphate. Collect urine samples in metal‑free container.
Stability in urine: LREFWHO Publication: Use of anticoagulants in diagnostic laboratory investigations, WHO/DIL/LAB/99.1 Rev.2:Jan 2002. | 3 days at 15‑25 °C |
3 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on
Colorimetric endpoint method
Sample and addition of R1
Addition of R3 and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Measuring range
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Lower limits of measurement
Limit of Blank and Limit of Detection
Serum/plasma
Limit of Blank | = 0.05 mmol/L (0.122 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Values below the Limit of Detection (< 0.10 mmol/L) will not be flagged by the instrument.
Urine
Limit of Blank | = 0.28 mmol/L (0.680 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Values below the Limit of Detection (< 0.56 mmol/L) will not be flagged by the instrument.
The Limit of Blank and Limit of Detection were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
Serum/plasma: | ||
Newborn: | 0.62‑0.91 mmol/L | (1.5‑2.2 mg/dL) |
5 months‑6 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
6‑12 years: | 0.70‑0.86 mmol/L | (1.7‑2.1 mg/dL) |
12‑20 years: | 0.70‑0.91 mmol/L | (1.7‑2.2 mg/dL) |
Adults: | 0.66‑1.07 mmol/L | (1.6‑2.6 mg/dL) |
60‑90 years: | 0.66‑0.99 mmol/L | (1.6‑2.4 mg/dL) |
> 90 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
Urine (24 h): | 3.0‑5.0 mmol/d | (72.9‑121.5 mg/d) |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL, 1.4 mval/L).
Serum/plasma
Icterus:
Hemolysis:
Hemolysis elevates results depending on the content of the analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Drugs: No interference was found at therapeutic concentrations using common drug panels.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.1 mg/dL, 3.4 mval/L).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
06407358190 | Magnesium Gen.2 (200 tests) | System‑ID 01 7486 3 |
Materials required (but not provided):
Calibrator f.a.s. (12 x 3 mL) | Code 401 | ||
12149435160 | Precinorm U plus (10 x 3 mL) | Code 300 | |
12149443160 | Precipath U plus (10 x 3 mL) | Code 301 | |
05947626160 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05947774160 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05172152190 | Diluent NaCl 9 % (119 mL) | System‑ID 08 6869 3 |
MG‑2: ACN 8701 (Serum/plasma)
MGU‑2: ACN 8704 (Urine)
SMG2: ACN 8688 (STAT, Serum/plasma, reaction time: 4)
SMG2U: ACN 8689 (STAT, Urine, reaction time: 4)
Ready for use
cobas c 701/702 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 18‑27 (STAT 4 / 6‑15) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R3 (STAT R2) | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (H2O) | ||
Normal | 3 µL | – | – |
Decreased | 1.5 µL | – | – |
Increased | 6 µL | – | – |
Application for urine
cobas c 701/702 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 18‑27 (STAT 4 / 6‑15) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R3 (STAT R2) | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 6 µL | 14 µL | 140 µL |
Decreased | 3 µL | 14 µL | 140 µL |
Increased | 12 µL | 14 µL | 140 µL |
See expiration date on cobas c pack label. | |
On‑board in use and refrigerated on the analyzer: | 10 days |
On‑board on the Reagent Manager | 24 hours |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in an internal protocol with repeatability (n = 21) and intermediate precision (3 aliquots per run, 1 run per day, 10 days). The following results were obtained:
Serum/plasma
MG‑2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.987 (2.40) | 0.005 (0.01) | 0.5 |
Precipath U | 1.81 (4.40) | 0.01 (0.02) | 0.5 |
Human serum A | 0.636 (1.55) | 0.005 (0.01) | 0.8 |
Human serum B | 0.982 (2.39) | 0.008 (0.02) | 0.8 |
Human serum C | 1.88 (4.57) | 0.01 (0.02) | 0.8 |
SMG2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.972 (2.36) | 0.005 (0.01) | 0.5 |
Precipath U | 1.79 (4.35) | 0.01 (0.02) | 0.3 |
Human serum A | 0.624 (1.52) | 0.005 (0.01) | 0.8 |
Human serum B | 0.976 (2.37) | 0.006 (0.01) | 0.6 |
Human serum C | 1.86 (4.52) | 0.01 (0.02) | 0.5 |
MG‑2/SMG2
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.974 (2.37) | 0.013 (0.03) | 1.3 |
Precipath U | 1.79 (4.35) | 0.02 (0.05) | 1.4 |
Human serum D | 0.626 (1.52) | 0.011 (0.03) | 1.7 |
Human serum E | 0.969 (2.35) | 0.013 (0.03) | 1.4 |
Human serum F | 1.95 (4.74) | 0.03 (0.07) | 1.5 |
Urine
MGU‑2
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 2.02 (4.91) | 0.02 (0.05) | 1.1 |
Control level 2 | 4.83 (11.7) | 0.02 (0.05) | 0.4 |
Human urine A | 1.43 (3.47) | 0.03 (0.07) | 2.3 |
Human urine B | 3.07 (7.46) | 0.02 (0.05) | 0.6 |
Human urine C | 8.29 (20.1) | 0.04 (0.10) | 0.5 |
SMG2U
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 2.01 (4.88) | 0.03 (0.07) | 1.3 |
Control level 2 | 4.78 (11.6) | 0.03 (0.07) | 0.6 |
Human urine A | 1.41 (3.43) | 0.02 (0.05) | 1.3 |
Human urine B | 3.03 (7.36) | 0.02 (0.05) | 0.7 |
Human urine C | 8.23 (20.0) | 0.05 (0.12) | 0.6 |
MGU‑2/SMG2U
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Control level 1 | 13.8 (33.5) | 0.2 (0.5) | 1.7 |
Control level 2 | 3.21 (7.80) | 0.12 (0.29) | 3.8 |
Human urine 1 | 2.89 (7.02) | 0.13 (0.32) | 4.6 |
Results for intermediate precision in urine were obtained on the Roche/Hitachi MODULAR P system.
Magnesium values for human serum/plasma and urine samples obtained on a
Serum/plasma
MG‑2
Sample size (n) = 87
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.027x - 0.02 mmol/L | y = 1.029x - 0.021 mmol/L |
τ = 0.958 | r = 0.998 |
The sample concentrations were between 0.560 and 1.94 mmol/L (1.36 and 4.71 mg/dL). |
SMG2
Sample size (n) = 86
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.012x - 0.010 mmol/L | y = 1.016x - 0.014 mmol/L |
τ = 0.959 | r = 0.998 |
The sample concentrations were between 0.560 and 1.94 mmol/L (1.36 and 4.71 mg/dL). |
Urine
Sample size (n) = 86
MGU‑2
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.013x + 0.010 mmol/L | y = 1.013x + 0.016 mmol/L |
τ = 0.990 | r = 1.000 |
The sample concentrations were between 0.600 and 10.3 mmol/L (1.46 and 25.0 mg/dL). |
SMG2U
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.000x + 0.020 mmol/L | y = 1.002x + 0.021 mmol/L |
τ = 0.989 | r = 1.000 |
The sample concentrations were between 0.600 and 10.3 mmol/L (1.46 and 25.0 mg/dL). |
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP‑magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRISa)/6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
R3 | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
a) TRIS = Tris(hydroxymethyl)‑aminomethane |
R1 is in position B and R3 (STAT R2) is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: 1-800-428-2336
Serum/plasma
For quality control, use control materials as listed in the \"Order information\" section.
In addition, other suitable control material can be used.
Urine
Quantitative urine controls are recommended for routine quality control.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum.
Plasma: Li‑heparin plasma.
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFWHO Publication: Use of anticoagulants in diagnostic laboratory investigations, WHO/DIL/LAB/99.1 Rev.2:Jan 2002. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C | |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesium ammonium phosphate. Collect urine samples in metal‑free container.
Stability in urine: LREFWHO Publication: Use of anticoagulants in diagnostic laboratory investigations, WHO/DIL/LAB/99.1 Rev.2:Jan 2002. | 3 days at 15‑25 °C |
3 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C | |
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on the cobas c 111 system.
Colorimetric endpoint method
Sample and addition of R1
Addition of SR and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Limit of Blank, Limit of Detection, and Limit of Quantitation:
Limit of Blank | = 0.05 mmol/L (0.12 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Quantitation | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Blank | = 0.28 mmol/L (0.68 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Limit of Quantitation | = 0.56 mmol/L (1.36 mg/dL) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a total error of 20 %. It has been determined using low concentration magnesium samples.
Newborn: | 0.62‑0.91 mmol/L | (1.5‑2.2 mg/dL) |
5 months‑6 years | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
6‑12 years | 0.70‑0.86 mmol/L | (1.7‑2.1 mg/dL) |
12‑20 years | 0.70‑0.91 mmol/L | (1.7‑2.2 mg/dL) |
Adults: | 0.66‑1.07 mmol/L | (1.6‑2.6 mg/dL) |
60‑90 years | 0.66‑0.99 mmol/L | (1.6‑2.4 mg/dL) |
> 90 years | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
Urine (24 h) | 3.0‑5.0 mmol/d |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Serum/plasma
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL).
Icterus:
Hemolysis:
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.13 mg/dL).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
Drugs: No interference was found at therapeutic concentrations using common drug panels.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on the cobas c 111 analyzer. For information about test combinations requiring special wash steps, please refer to the latest version of the carry over evasion list found with the CLEAN Method Sheet and the operator’s manual for further instructions.
Where required, special wash/carry-over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which kit(s) can be used | |
08900019190 | Magnesium Gen.2 (2 × 50 tests) | cobasc 111 |
Materials required (but not provided):
10759350190 | Calibrator f.a.s. (12 × 3 mL) | Code 401 | |
10759350360 | Calibrator f.a.s. (12 × 3 mL, for USA) | Code 401 | |
12149435122 | Precinorm U plus (10 × 3 mL) | Code 300 | |
12149435160 | Precinorm U plus (10 × 3 mL, for USA) | Code 300 | |
12149443122 | Precipath U plus (10 × 3 mL) | Code 301 | |
12149443160 | Precipath U plus (10 × 3 mL, for USA) | Code 301 | |
05117003190 | PreciControl ClinChem Multi 1 (20 × 5 mL) | Code 391 | |
05947626190 | PreciControl ClinChem Multi 1 (4 × 5 mL) | Code 391 | |
05947626160 | PreciControl ClinChem Multi 1 (4 × 5 mL, for USA) | Code 391 | |
05117216190 | PreciControl ClinChem Multi 2 (20 × 5 mL) | Code 392 | |
05947774190 | PreciControl ClinChem Multi 2 (4 × 5 mL) | Code 392 | |
05947774160 | PreciControl ClinChem Multi 2 (4 × 5 mL, for USA) | Code 392 | |
04774230190 | NaCl Diluent 9 % | Code 951 | |
11930630001 | Chimneys |
MG‑2: ACN 701
MGU‑2: ACN 704
Ready for use
Place a chimney in R1 before use.
Absorption of atmospheric CO2 by the opened reagent bottles leads to impaired reagent stability. This kit therefore requires the use of chimneys which reduce the uptake of CO2 by the reagents. The chimneys should be placed directly into the appropriate reagent. The chimneys can be reused for reagent bottles within the same kit. However, to avoid contamination of the reagent with detergent or dilution of the reagent with water it is not permitted to wash the chimneys before reuse.
Measuring mode | Absorbance |
Abs. calculation mode | Endpoint |
Reaction direction | Decrease |
Wavelength A/B | 629/520 nm |
Calc. first/last | 16/24 |
Unit | mmol/L |
Serum/plasma | |
Reaction mode | R1‑S‑SR |
Urine | |
Reaction mode | R1‑S‑SR |
Predilution factor | 5.5 |
Serum, plasma and urine | Diluent (H2O) | |
R1 | 97 µL | |
Sample | 3 µL | 20 µL |
SR | 97 µL | |
Total volume | 217 µL |
Shelf life at 15‑25 °C: | See expiration date on reagent |
On‑board in use and refrigerated on the analyzer: | 4 weeks |
Shelf life at 2‑8 °C: | See expiration date on reagent |
On‑board in use and refrigerated on the analyzer: | 4 weeks |
Calibrator | Calibrator f.a.s. |
Calibration mode | Linear regression |
Calibration replicate | Duplicate recommended |
Calibration interval | - each lot |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against atomic absorption spectrometry.
For the USA, this method has been standardized against SRM 956.
Representative performance data on the cobas c 111 analyzer are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5‑A3 requirements with repeatability (n = 84) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days).
The following results were obtained:
Repeatability | Mean | SD | CV |
|---|---|---|---|
PCCC1b) | 0.860 (2.09) | 0.006 (0.015) | 0.7 |
PCCC2c) | 1.32 (3.21) | 0.010 (0.024) | 0.8 |
Human serum 1 | 0.316 (0.768) | 0.004 (0.010) | 1.4 |
Human serum 2 | 0.807 (1.96) | 0.006 (0.015) | 0.8 |
Human serum 3 | 1.09 (2.65) | 0.008 (0.019) | 0.7 |
Human serum 4 | 1.28 (3.11) | 0.011 (0.027) | 0.8 |
Human serum 5 | 1.64 (3.99) | 0.013 (0.032) | 0.8 |
Intermediate precision | Mean | SD | CV |
|---|---|---|---|
PCCC1 FREFPreciControl ClinChem Multi 1 | 0.860 (2.09) | 0.012 (0.029) | 1.3 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 1.32 (3.21) | 0.019 (0.046) | 1.5 |
Human serum 1 | 0.316 (0.768) | 0.009 (0.022) | 2.9 |
Human serum 2 | 0.807 (1.96) | 0.012 (0.029) | 1.4 |
Human serum 3 | 1.09 (2.65) | 0.014 (0.034) | 1.3 |
Human serum 4 | 1.28 (3.11) | 0.020 (0.049) | 1.6 |
Human serum 5 | 1.64 (3.98) | 0.027 (0.066) | 1.6 |
Repeatability | Mean | SD | CV |
|---|---|---|---|
Liquicheck 1 | 1.67 (4.06) | 0.018 (0.044) | 1.1 |
Liquicheck 2 | 3.56 (8.65) | 0.031 (0.075) | 0.9 |
Human urine 1 | 0.814 (1.98) | 0.036 (0.087) | 4.5 |
Human urine 2 | 1.18 (2.87) | 0.017 (0.041) | 1.5 |
Human urine 3 | 4.14 (10.1) | 0.044 (1.07) | 1.1 |
Human urine 4 | 6.22 (15.1) | 0.100 (2.43) | 1.6 |
Human urine 5 | 7.75 (18.8) | 0.031 (0.075) | 0.4 |
Intermediate precision | Mean | SD | CV |
|---|---|---|---|
Liquicheck 1 | 1.67 (4.06) | 0.045 (0.109) | 2.7 |
Liquicheck 2 | 3.56 (8.65) | 0.053 (0.129) | 1.5 |
Human urine 1 | 0.814 (1.98) | 0.050 (0.122) | 6.1 |
Human urine 2 | 1.18 (2.87) | 0.048 (0.117) | 4.1 |
Human urine 3 | 4.14 (10.1) | 0.075 (0.182) | 1.8 |
Human urine 4 | 6.22 (15.1) | 0.138 (0.335) | 2.2 |
Human urine 5 | 7.75 (18.8) | 0.183 (0.445) | 2.4 |
Magnesium values for human serum, plasma and urine samples obtained on a cobas c 111 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi COBAS INTEGRA 400 plus analyzer (x).
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.02x - 0.002 mmol/L | y = 1.02x - 0.002 mmol/L |
τ = 0.977 | r = 1.000 |
The sample concentrations were between 0.154 and 1.89 mmol/L (0.374 and 4.59 mg/dL).
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.982x + 0.040 mmol/L | y = 0.984x + 0.035 mmol/L |
τ = 0.977 | r = 1.000 |
The sample concentrations were between 0.633 and 10.9 mmol/L (1.54 and 26.5 mg/dL).
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP-magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRIS FREFTris(hydroxymethyl)‑aminomethane /6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
SR | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590, USA: 1-800-428-2336
Serum/plasma
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
Urine
Quantitative urine controls are recommended for routine quality control.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li-heparin plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Chelating anticoagulants such as EDTA, Fluoride and Oxalate must be avoided. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
Urine: Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesiumammonium phosphate. Collect urine samples in metal-free container.
See the limitations and interferences section for details about possible sample interferences.
Stability in serum/plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 7 days at 15‑25 °C 7 days at 2‑8 °C 1 year at (−15)‑(−25) °C |
Stability in urine: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 3 days at 15‑25 °C 3 days at 2‑8 °C 1 year at (−15)‑(−25) °C |
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on the cobas c 111 system.
Colorimetric endpoint method
Sample and addition of R1
Addition of SR and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Limit of Blank, Limit of Detection, and Limit of Quantitation:
Limit of Blank | = 0.05 mmol/L (0.12 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Quantitation | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Blank | = 0.28 mmol/L (0.68 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Limit of Quantitation | = 0.56 mmol/L (1.36 mg/dL) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a total error of 20 %. It has been determined using low concentration magnesium samples.
Newborn: | 0.62‑0.91 mmol/L | (1.5‑2.2 mg/dL) |
5 months‑6 years | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
6‑12 years | 0.70‑0.86 mmol/L | (1.7‑2.1 mg/dL) |
12‑20 years | 0.70‑0.91 mmol/L | (1.7‑2.2 mg/dL) |
Adults: | 0.66‑1.07 mmol/L | (1.6‑2.6 mg/dL) |
60‑90 years | 0.66‑0.99 mmol/L | (1.6‑2.4 mg/dL) |
> 90 years | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
Urine (24 h) | 3.0‑5.0 mmol/d | (72.9‑121.5 mg/d) |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Serum/plasma
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL).
Icterus:
Hemolysis:
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.13 mg/dL).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
Drugs: No interference was found at therapeutic concentrations using common drug panels.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on the cobas c 111 analyzer. For information about test combinations requiring special wash steps, please refer to the latest version of the carry-over evasion list found with the CLEAN Method Sheet and the operator’s manual for further instructions.
Where required, special wash/carry-over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which kit(s) can be used | |
08900019190 | Magnesium Gen.2 (2 × 50 tests) | cobas c 111 |
Materials required (but not provided):
Calibrator f.a.s. (12 × 3 mL) | Code 401 | ||
12149435160 | Precinorm U plus (10 × 3 mL) | Code 300 | |
12149443160 | Precipath U plus (10 × 3 mL) | Code 301 | |
05947626160 | PreciControl ClinChem Multi 1 (4 × 5 mL) | Code 391 | |
05947774160 | PreciControl ClinChem Multi 2 (4 × 5 mL) | Code 392 | |
04774230190 | NaCl Diluent 9 % | Code 951 | |
11930630001 | Chimneys |
MG‑2: ACN 701
MGU‑2: ACN 704
Ready for use
Place a chimney in R1 before use.
Absorption of atmospheric CO2 by the opened reagent bottles leads to impaired reagent stability. This kit therefore requires the use of chimneys which reduce the uptake of CO2 by the reagents. The chimneys should be placed directly into the appropriate reagent. The chimneys can be reused for reagent bottles within the same kit. However, to avoid contamination of the reagent with detergent or dilution of the reagent with water it is not permitted to wash the chimneys before reuse.
Measuring mode | Absorbance |
Abs. calculation mode | Endpoint |
Reaction direction | Decrease |
Wavelength A/B | 629/520 nm |
Calc. first/last | 16/24 |
Unit | mmol/L |
Serum/plasma | |
Reaction mode | R1‑S‑SR |
Urine | |
Reaction mode | R1‑S‑SR |
Predilution factor | 5.5 |
Serum, plasma and urine | Diluent (H2O) | |
R1 | 97 µL | |
Sample | 3 µL | 20 µL |
SR | 97 µL | |
Total volume | 217 µL |
See expiration date on reagent | |
4 weeks |
Calibrator | Calibrator f.a.s. |
Calibration mode | Linear regression |
Calibration replicate | Duplicate recommended |
Calibration interval |
|
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Representative performance data on the cobas c 111 analyzer are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5‑A3 requirements with repeatability (n = 84) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days).
The following results were obtained:
Repeatability | Mean | SD | CV |
|---|---|---|---|
PCCC1b) | 0.860 (2.09) | 0.006 (0.015) | 0.7 |
PCCC2c) | 1.32 (3.21) | 0.010 (0.024) | 0.8 |
Human serum 1 | 0.316 (0.768) | 0.004 (0.010) | 1.4 |
Human serum 2 | 0.807 (1.96) | 0.006 (0.015) | 0.8 |
Human serum 3 | 1.09 (2.65) | 0.008 (0.019) | 0.7 |
Human serum 4 | 1.28 (3.11) | 0.011 (0.027) | 0.8 |
Human serum 5 | 1.64 (3.99) | 0.013 (0.032) | 0.8 |
Intermediate precision | Mean | SD | CV |
|---|---|---|---|
PCCC1 FREFPreciControl ClinChem Multi 1 | 0.860 (2.09) | 0.012 (0.029) | 1.3 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 1.32 (3.21) | 0.019 (0.046) | 1.5 |
Human serum 1 | 0.316 (0.768) | 0.009 (0.022) | 2.9 |
Human serum 2 | 0.807 (1.96) | 0.012 (0.029) | 1.4 |
Human serum 3 | 1.09 (2.65) | 0.014 (0.034) | 1.3 |
Human serum 4 | 1.28 (3.11) | 0.020 (0.049) | 1.6 |
Human serum 5 | 1.64 (3.98) | 0.027 (0.066) | 1.6 |
Repeatability | Mean | SD | CV |
|---|---|---|---|
Liquicheck 1 | 1.67 (4.06) | 0.018 (0.044) | 1.1 |
Liquicheck 2 | 3.56 (8.65) | 0.031 (0.075) | 0.9 |
Human urine 1 | 0.814 (1.98) | 0.036 (0.087) | 4.5 |
Human urine 2 | 1.18 (2.87) | 0.017 (0.041) | 1.5 |
Human urine 3 | 4.14 (10.1) | 0.044 (1.07) | 1.1 |
Human urine 4 | 6.22 (15.1) | 0.100 (2.43) | 1.6 |
Human urine 5 | 7.75 (18.8) | 0.031 (0.075) | 0.4 |
Intermediate precision | Mean | SD | CV |
|---|---|---|---|
Liquicheck 1 | 1.67 (4.06) | 0.045 (0.109) | 2.7 |
Liquicheck 2 | 3.56 (8.65) | 0.053 (0.129) | 1.5 |
Human urine 1 | 0.814 (1.98) | 0.050 (0.122) | 6.1 |
Human urine 2 | 1.18 (2.87) | 0.048 (0.117) | 4.1 |
Human urine 3 | 4.14 (10.1) | 0.075 (0.182) | 1.8 |
Human urine 4 | 6.22 (15.1) | 0.138 (0.335) | 2.2 |
Human urine 5 | 7.75 (18.8) | 0.183 (0.445) | 2.4 |
Magnesium values for human serum, plasma and urine samples obtained on a cobas c 111 analyzer (y) were compared with those determined using the corresponding reagent on a
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.02x - 0.002 mmol/L | y = 1.02x - 0.002 mmol/L |
τ = 0.977 | r = 1.000 |
The sample concentrations were between 0.154 and 1.89 mmol/L (0.374 and 4.59 mg/dL).
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.982x + 0.040 mmol/L | y = 0.984x + 0.035 mmol/L |
τ = 0.977 | r = 1.000 |
The sample concentrations were between 0.633 and 10.9 mmol/L (1.54 and 26.5 mg/dL).
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP-magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRIS FREFTris(hydroxymethyl)‑aminomethane /6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
SR | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: 1-800-428-2336
Serum/plasma
For quality control, use control materials as listed in the \"Order information\" section.
In addition, other suitable control material can be used.
Urine
Quantitative urine controls are recommended for routine quality control.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li-heparin plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 7 days at 15‑25 °C 7 days at 2‑8 °C 1 year at (−15)‑(−25) °C |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesiumammonium phosphate. Collect urine samples in metal-free container.
Stability in urine: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 3 days at 15‑25 °C 3 days at 2‑8 °C 1 year at (−15)‑(−25) °C |
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on the COBAS INTEGRA 400 plus system.
Colorimetric endpoint method
Sample and addition of R1
Addition of SR and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Limit of Blank, Limit of Detection, and Limit of Quantitation:
Limit of Blank | = 0.05 mmol/L (0.12 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Quantitation | = 0.10 mmol/L (0.243 mg/dL) |
Limit of Blank | = 0.28 mmol/L (0.68 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
Limit of Quantitation | = 0.56 mmol/L (1.36 mg/dL) |
The Limit of Blank, Limit of Detection and Limit of Quantitation were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A2 requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
The Limit of Quantitation is the lowest analyte concentration that can be reproducibly measured with a total error of 20 %. It has been determined using low concentration magnesium samples.
Newborn: | 0.62‑0.91 mmol/L | (1.5‑2.2 mg/dL) |
5 months‑6 years | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
6‑12 years | 0.70‑0.86 mmol/L | (1.7‑2.1 mg/dL) |
12‑20 years | 0.70‑0.91 mmol/L | (1.7‑2.2 mg/dL) |
Adults: | 0.66‑1.07 mmol/L | (1.6‑2.6 mg/dL) |
60‑90 years | 0.66‑0.99 mmol/L | (1.6‑2.4 mg/dL) |
> 90 years | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
Urine (24 h) | 3.0‑5.0 mmol/d |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Serum/plasma
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL).
Icterus:
Hemolysis:
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.13 mg/dL).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
Drugs: No interference was found at therapeutic concentrations using common drug panels.
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on COBAS INTEGRA analyzers. Refer to the CLEAN Method Sheet for further instructions and for the latest version of the Extra wash cycle list.
Where required, special wash/carry-over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
06481647190 | Magnesium Gen.2 (250 tests) | System-ID 07 7486 3 | COBAS INTEGRA 400 plus |
Materials required (but not provided):
10759350190 | Calibrator f.a.s. (12 × 3 mL) | System-ID 07 3718 6 | |
10759350360 | Calibrator f.a.s. (12 × 3 mL, for USA) | System-ID 07 3718 6 | |
12149435122 | Precinorm U plus (10 × 3 mL) | System-ID 07 7999 7 | |
12149435160 | Precinorm U plus (10 × 3 mL, for USA) | System-ID 07 7999 7 | |
12149443122 | Precipath U plus (10 × 3 mL) | System-ID 07 8000 6 | |
12149443160 | Precipath U plus (10 × 3 mL, for USA) | System-ID 07 8000 6 | |
05117003190 | PreciControl ClinChem Multi 1 (20 × 5 mL) | System-ID 07 7469 3 | |
05947626190 | PreciControl ClinChem Multi 1 (4 × 5 mL) | System-ID 07 7469 3 | |
05947626160 | PreciControl ClinChem Multi 1 (4 × 5 mL, for USA) | System-ID 07 7469 3 | |
05117216190 | PreciControl ClinChem Multi 2 (20 × 5 mL) | System-ID 07 7470 7 | |
05947774190 | PreciControl ClinChem Multi 2 (4 × 5 mL) | System-ID 07 7470 7 | |
05947774160 | PreciControl ClinChem Multi 2 (4 × 5 mL, for USA) | System-ID 07 7470 7 | |
20756350322 | NaCl Diluent 9 % (6 × 22 mL) | System‑ID 07 5635 0 |
Test MG‑2, test ID 0‑701; test MGU‑2, test ID 0‑704
Ready for use
Measuring mode | Absorbance |
Abs. calculation mode | Endpoint |
Reaction direction | Decrease |
Wavelength A/B | 629/520 nm |
Calc. first/last | 33/46 |
Unit | mmol/L |
Serum, plasma | |
Reaction mode | R1‑S‑SR |
Urine | |
Reaction mode | R1‑S‑SR |
Predilution factor | 5.5 |
Serum, plasma, and urine | Diluent (H2O) | |
R1 | 97 µL | |
Sample | 3 µL | 20 µL |
SR | 97 µL | |
Total volume | 217 µL |
Shelf life at 15‑25 °C | See expiration date on cobas c pack label |
On-board in use at 10‑15 °C | 12 weeks |
Calibrator | Calibrator f.a.s. Use deionized water as zero calibrator. |
Calibration mode | Linear regression |
Calibration replicate | Duplicate recommended |
Calibration interval | Each lot and as required following quality control procedures. |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against atomic absorption spectrometry.
For the USA, this method has been standardized against SRM 956.
Representative performance data on the COBAS INTEGRA analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP5‑A3 requirements with repeatability (n = 84) and intermediate precision (2 aliquots per run, 2 runs per day, 21 days).
The following results were obtained:
Repeatability | Mean | SD | CV |
|---|---|---|---|
PCCC1b) | 0.877 (2.13) | 0.011 (0.027) | 1.3 |
PCCC2c) | 1.36 (3.30) | 0.008 (0.019) | 0.6 |
Human serum 1 | 0.318 (0.773) | 0.009 (0.022) | 2.8 |
Human serum 2 | 0.818 (1.99) | 0.009 (0.022) | 1.1 |
Human serum 3 | 1.12 (2.72) | 0.011 (0.027) | 0.9 |
Human serum 4 | 1.31 (3.18) | 0.011 (0.027) | 0.9 |
Human serum 5 | 1.67 (4.06) | 0.025 (0.061) | 1.5 |
Intermediate precision | Mean | SD | CV |
|---|---|---|---|
PCCC1 FREFPreciControl ClinChem Multi 1 | 0.877 (2.13) | 0.015 (0.036) | 1.7 |
PCCC2 FREFPreciControl ClinChem Multi 2 | 1.35 (3.28) | 0.011 (0.027) | 0.8 |
Human serum 1 | 0.318 (0.773) | 0.012 (0.029) | 3.8 |
Human serum 2 | 0.818 (1.99) | 0.010 (0.024) | 1.2 |
Human serum 3 | 1.12 (2.72) | 0.011 (0.027) | 0.9 |
Human serum 4 | 1.31 (3.18) | 0.012 (0.029) | 0.9 |
Human serum 5 | 1.67 (4.06) | 0.026 (0.063) | 1.5 |
Repeatability | Mean | SD | CV |
|---|---|---|---|
Liquicheck 1 | 1.59 (3.86) | 0.065 (0.158) | 4.0 |
Liquicheck 2 | 3.70 (8.99) | 0.062 (0.151) | 1.7 |
Human urine 1 | 0.867 (2.11) | 0.043 (0.104) | 5.0 |
Human urine 2 | 1.25 (3.04) | 0.054 (0.131) | 4.3 |
Human urine 3 | 3.97 (9.65) | 0.050 (0.122) | 1.3 |
Human urine 4 | 6.94 (16.9) | 0.098 (0.238) | 1.4 |
Human urine 5 | 8.79 (21.4) | 0.161 (0.391) | 1.8 |
Intermediate precision | Mean | SD | CV |
|---|---|---|---|
Liquicheck 1 | 1.59 (3.86) | 0.084 (0.204) | 5.2 |
Liquicheck 2 | 3.71 (9.02) | 0.105 (0.255) | 2.8 |
Human urine 1 | 0.867 (2.11) | 0.053 (0.124) | 6.1 |
Human urine 2 | 1.25 (3.04) | 0.058 (0.141) | 4.6 |
Human urine 3 | 3.97 (9.65) | 0.078 (0.190) | 2.0 |
Human urine 4 | 6.94 (16.9) | 0.163 (0.396) | 2.3 |
Human urine 5 | 8.79 (21.8) | 0.246 (0.598) | 2.8 |
Magnesium values for human serum, plasma and urine samples obtained on a COBAS INTEGRA 400 plus analyzer (y) were compared with those determined using the corresponding reagent on a
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 0.981x + 0.0416 mmol/L | y = 0.983x + 0.0402 mmol/L |
τ = 0.976 | r = 1.000 |
The sample concentrations were between 0.130 and 1.86 mmol/L (0.316 and 4.52 mg/dL).
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.016x + 0.0115 mmol/L | y = 1.014x + 0.0236 mmol/L |
τ = 0.970 | r = 1.000 |
The sample concentrations were between 0.610 and 10.8 mmol/L (1.48 and 26.2 mg/dL).
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP-magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRIS FREFTris(hydroxymethyl)‑aminomethane /6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
SR | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
R1 is in position B and SR is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590, USA: 1-800-428-2336
Quality control serum, plasma | Precinorm U plus or PreciControl ClinChem Multi 1 Precipath U plus or PreciControl ClinChem Multi 2 |
Quality control urine | Quantitative urine controls are recommended for routine quality control. |
Control interval | 24 hours recommended |
Control sequence | User defined |
Control after calibration | Recommended |
For quality control, use control materials as listed in the “Order information” section. In addition, other suitable control material can be used.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li-heparin plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested. Chelating anticoagulants such as EDTA, Fluoride and Oxalate must be avoided. Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
Urine: Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesiumammonium phosphate. Collect urine samples in metal-free container.
See the limitations and interferences section for details about possible sample interferences.
Stability in serum/plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 7 days at 15‑25 °C 7 days at 2‑8 °C 1 year at (−15)‑(−25) °C |
Stability in urine: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 3 days at 15‑25 °C 3 days at 2‑8 °C 1 year at (−15)‑(−25) °C |
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
In vitro test for the quantitative determination of magnesium in human serum, plasma and urine on Roche/Hitachi cobas c systems.
Colorimetric endpoint method
Sample and addition of R1
Addition of R2 and start of reaction:
In alkaline solution, magnesium forms a purple complex with xylidyl blue, diazonium salt. The magnesium concentration is measured photometrically via the decrease in the xylidyl blue absorbance.
Measuring range
Serum/plasma
0.10‑2.0 mmol/L (0.243‑4.86 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Urine
0.56‑11.0 mmol/L (1.36‑26.7 mg/dL)
Determine samples having higher concentrations via the rerun function. Dilution of samples via the rerun function is a 1:2 dilution. Results from samples diluted using the rerun function are automatically multiplied by a factor of 2.
Lower limits of measurement
Limit of Blank and Limit of Detection
Serum/plasma
Limit of Blank | = 0.05 mmol/L (0.122 mg/dL) |
Limit of Detection | = 0.10 mmol/L (0.243 mg/dL) |
Urine
Limit of Blank | = 0.28 mmol/L (0.680 mg/dL) |
Limit of Detection | = 0.56 mmol/L (1.36 mg/dL) |
The Limit of Blank and Limit of Detection were determined in accordance with the CLSI (Clinical and Laboratory Standards Institute) EP17‑A requirements.
The Limit of Blank is the 95th percentile value from n ≥ 60 measurements of analyte‑free samples over several independent series. The Limit of Blank corresponds to the concentration below which analyte‑free samples are found with a probability of 95 %.
The Limit of Detection is determined based on the Limit of Blank and the standard deviation of low concentration samples.
The Limit of Detection corresponds to the lowest analyte concentration which can be detected (value above the Limit of Blank with a probability of 95 %).
Serum/plasma: | ||
Newborn: | 0.62‑0.91 mmol/L | (1.5‑2.2 mg/dL) |
5 months‑6 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
6‑12 years: | 0.70‑0.86 mmol/L | (1.7‑2.1 mg/dL) |
12‑20 years: | 0.70‑0.91 mmol/L | (1.7‑2.2 mg/dL) |
Adults: | 0.66‑1.07 mmol/L | (1.6‑2.6 mg/dL) |
60‑90 years: | 0.66‑0.99 mmol/L | (1.6‑2.4 mg/dL) |
> 90 years: | 0.70‑0.95 mmol/L | (1.7‑2.3 mg/dL) |
Urine (24 h): | ||
3.0‑5.0 mmol/d | (72.9‑121.5 mg/d) |
Roche has not evaluated reference ranges in a pediatric population.
Each laboratory should investigate the transferability of the expected values to its own patient population and if necessary determine its own reference ranges.
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 0.7 mmol/L (1.7 mg/dL, 1.4 mval/L).
Serum/plasma
Icterus:
Hemolysis:
Hemolysis elevates results depending on the content of the analyte in the lysed erythrocytes.
Lipemia (Intralipid):
Drugs: No interference was found at therapeutic concentrations using common drug panels.
In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.
Urine
Criterion: Recovery within ± 10 % of initial value at a magnesium concentration of 1.7 mmol/L (4.1 mg/dL, 3.4 mval/L).
Urea: No significant interference from urea up to a concentration of 1500 mmol/L (9009 mg/dL).
For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.
ACTION REQUIRED
Special Wash Programming: The use of special wash steps is mandatory when certain test combinations are run together on Roche/Hitachi cobas c systems. The latest version of the carry‑over evasion list can be found with the NaOHD-SMS-SmpCln1+2-SCCS Method Sheets. For further instructions refer to the operator’s manual. cobas c 502 analyzer: All special wash programming necessary for avoiding carry‑over is available via the cobas link, manual input is required in certain cases.
Where required, special wash/carry‑over evasion programming must be implemented prior to reporting results with this test.
|
| Analyzer(s) on which cobas c pack(s) can be used | |
06481647 190 | Magnesium Gen.2 (250 tests) | System‑ID 07 7486 3 | Roche/Hitachi cobas c 311, cobas c 501/502 |
Materials required (but not provided):
10759350 190 | Calibrator f.a.s. (12 x 3 mL) | Code 401 | |
10759350 360 | Calibrator f.a.s. (12 x 3 mL, for USA) | Code 401 | |
12149435 122 | Precinorm U plus (10 x 3 mL) | Code 300 | |
12149435 160 | Precinorm U plus (10 x 3 mL, for USA) | Code 300 | |
12149443 122 | Precipath U plus (10 x 3 mL) | Code 301 | |
12149443 160 | Precipath U plus (10 x 3 mL, for USA) | Code 301 | |
05117003 190 | PreciControl ClinChem Multi 1 (20 x 5 mL) | Code 391 | |
05947626 190 | PreciControl ClinChem Multi 1 (4 x 5 mL) | Code 391 | |
05947626 160 | PreciControl ClinChem Multi 1 (4 x 5 mL, for USA) | Code 391 | |
05117216 190 | PreciControl ClinChem Multi 2 (20 x 5 mL) | Code 392 | |
05947774 190 | PreciControl ClinChem Multi 2 (4 x 5 mL) | Code 392 | |
05947774 160 | PreciControl ClinChem Multi 2 (4 x 5 mL, for USA) | Code 392 | |
04489357 190 | Diluent NaCl 9 % (50 mL) | System‑ID 07 6869 3 |
For cobas c 311/501 analyzers:
MG‑2: ACN 701 (serum and plasma)
MGU‑2: ACN 704 (urine)
SMG2: ACN 688 (STAT, serum and plasma, reaction time: 4)
SMG2U: ACN 689 (STAT, urine, reaction time: 4)
For cobas c 502 analyzer:
MG‑2: ACN 8701 (serum and plasma)
MGU‑2: ACN 8704 (urine)
SMG2: ACN 8688 (STAT, serum and plasma, reaction time: 4)
SMG2U: ACN 8689 (STAT, urine, reaction time: 4)
Ready for use
cobas c 311 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 6‑17 (STAT 4 / 6‑17) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R2 | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3 µL | – | – |
Decreased | 9 µL | 20 µL | 100 µL |
Increased | 3 µL | – | – |
cobas c 501 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 10‑25 (STAT 4 / 10‑25) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R2 | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3 µL | – | – |
Decreased | 9 µL | 20 µL | 100 µL |
Increased | 3 µL | – | – |
cobas c 502 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 10‑25 (STAT 4 / 10‑25) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | – | |
R2 | 97 µL | – | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 3 µL | – | – |
Decreased | 9 µL | 20 µL | 100 µL |
Increased | 6 µL | – | – |
Application for urine
cobas c 311 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 6‑17 (STAT 4 / 6‑17) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | - | |
R2 | 97 µL | - | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 6 µL | 14 µL | 140 µL |
Decreased | 3 µL | 14 µL | 140 µL |
Increased | 6 µL | 14 µL | 140 µL |
cobas c 501 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 10‑25 (STAT 4 / 10‑25) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | - | |
R2 | 97 µL | - | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 6 µL | 14 µL | 140 µL |
Decreased | 3 µL | 14 µL | 140 µL |
Increased | 6 µL | 14 µL | 140 µL |
cobas c 502 test definition | |||
Assay type | 2‑Point End | ||
Reaction time / Assay points | 10 / 10‑25 (STAT 4 / 10‑25) | ||
Wavelength (sub/main) | 505/600 nm | ||
Reaction direction | Decrease | ||
Units | mmol/L (mg/dL, mval/L) | ||
Reagent pipetting | Diluent (H2O) | ||
R1 | 97 µL | - | |
R2 | 97 µL | - | |
Sample volumes | Sample | Sample dilution | |
Sample | Diluent (NaCl) | ||
Normal | 6 µL | 14 µL | 140 µL |
Decreased | 3 µL | 14 µL | 140 µL |
Increased | 12 µL | 14 µL | 140 µL |
MG | |
Shelf life at 15‑25 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 12 weeks |
Diluent NaCl 9 % | |
Shelf life at 2‑8 °C: | See expiration date on cobas c pack label. |
On‑board in use and refrigerated on the analyzer: | 12 weeks |
Calibrators | S1: H2O S2: C.f.a.s. |
Calibration mode | Linear |
Calibration frequency | 2‑point calibration |
Calibration interval may be extended based on acceptable verification of calibration by the laboratory.
Traceability: This method has been standardized against atomic absorption spectrometry.
For the USA, this method has been standardized against SRM 956.
Representative performance data on the analyzers are given below. Results obtained in individual laboratories may differ.
Precision was determined using human samples and controls in accordance with the CLSI (Clinical and Laboratory Standards Institue) EP5 requirements with repeatability and intermediate precision (2 aliquots per run, 2 runs per day, 21 days).
The following results were obtained:
Serum/plasma
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.891 (2.17) | 0.008 (0.02) | 0.9 |
Precipath U | 1.73 (4.20) | 0.01 (0.02) | 0.8 |
Human serum 1 | 0.588 (1.43) | 0.006 (0.01) | 1.1 |
Human serum 2 | 0.797 (1.94) | 0.007 (0.02) | 0.8 |
Human serum 3 | 1.35 (3.3) | 0.01 (0.0) | 0.7 |
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Precinorm U | 0.891 (2.17) | 0.009 (0.02) | 1.0 |
Precipath U | 1.73 (4.20) | 0.02 (0.05) | 1.0 |
Human serum 1 | 0.588 (1.43) | 0.008 (0.02) | 1.3 |
Human serum 2 | 0.797 (1.94) | 0.009 (0.02) | 1.1 |
Human serum 3 | 1.35 (3.3) | 0.01(0.0) | 0.9 |
Urine
Repeatability | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Liquicheck 1 | 2.16 (5.25) | 0.03 (0.07) | 1.4 |
Liquicheck 2 | 5.16 (12.5) | 0.04 (0.1) | 0.8 |
Human urine 1 | 1.50 (3.65) | 0.03 (0.07) | 1.8 |
Human urine 2 | 6.29 (15.3) | 0.05 (0.1) | 0.8 |
Human urine 3 | 9.59 (23.3) | 0.06 (0.2) | 0.6 |
Intermediate precision | Mean mmol/L (mg/dL) | SD mmol/L (mg/dL) | CV % |
Liquicheck 1 | 2.16 (5.25) | 0.03 (0.07) | 1.5 |
Liquicheck 2 | 5.16 (12.5) | 0.06 (0.2) | 1.1 |
Human urine 1 | 1.50 (3.65) | 0.03 (0.07) | 2.1 |
Human urine 2 | 6.29 (15.3) | 0.06 (0.2) | 0.9 |
Human urine 3 | 9.59 (23.3) | 0.07 (0.2) | 0.8 |
Magnesium values for human serum/plasma and urine samples obtained on a Roche/Hitachi cobas c 501 analyzer (y) were compared with those determined using the corresponding reagent on a Roche/Hitachi 917 analyzer (x).
Serum/plasma
Sample size (n) = 75
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.029x - 0.015 mmol/L | y = 1.031x - 0.019 mmol/L |
τ = 0.985 | r = 0.999 |
The sample concentrations were between 0.308 and 1.67 mmol/L (0.748 and 4.06 mg/dL). |
Urine
Sample size (n) = 57
Passing/Bablok LREFBablok W, Passing H, Bender R, et al. A general regression procedure for method transformation. Application of linear regression procedures for method comparison studies in clinical chemistry, Part III. J Clin Chem Clin Biochem 1988 Nov;26(11):783-790. | Linear regression |
y = 1.025x + 0.043 mmol/L | y = 1.025x + 0.038 mmol/L |
τ = 0.994 | r = 1.00 |
The sample concentrations were between 0.630 and 10.5 mmol/L (1.53 and 25.5 mg/dL). |
Magnesium along with potassium is a major intracellular cation. Mg2+ is a cofactor of many enzyme systems. Thus, all ATP‑dependent enzymatic reactions require Mg2+ as a cofactor in the ATP‑magnesium complex. Approximately 69 % of magnesium ions are stored in bone. The rest are part of the intermediary metabolism, about 70 % being present in free form while the other 30 % is bound to proteins (especially albumin), citrates, phosphate, and other complex formers. The Mg2+ serum level is kept constant within very narrow limits (0.65‑1.05 mmol/L). Regulation takes place mainly via the kidneys, especially via the ascending loop of Henle.
This assay is used for diagnosing and monitoring hypomagnesemia (magnesium deficiency) and hypermagnesemia (magnesium excess). Numerous studies have shown a correlation between magnesium deficiency and changes in calcium‑, potassium‑ and phosphate‑homeostasis which are associated with cardiac disorders such as ventricular arrhythmias that cannot be treated by conventional therapy, increased sensitivity to digoxin, coronary artery spasms, and sudden death. Additional concurrent symptoms include neuromuscular and neuropsychiatric disorders. Hypermagnesemia is found in acute and chronic renal failure, magnesium excess, and magnesium release from the intracellular space.
In addition to atomic absorption spectrometry (AAS), complexometric methods can also be used to determine magnesium.
The method described here is based on the reaction of magnesium with xylidyl blue in alkaline solution containing EGTA to mask the calcium in the sample.
Urine magnesium levels are determined in magnesium depletion tests.
R1 | TRISa /6‑aminocaproic acid buffer: 500 mmol/L, pH 11.25; EGTA: 129 µmol/L; preservative |
R2 | Xylidyl blue: 0.28 mmol/L; detergent; preservative |
a) TRIS = Tris(hydroxymethyl)‑aminomethane
R1 is in position B and R2 is in position C.
For in vitro diagnostic use for health care professionals. Exercise the normal precautions required for handling all laboratory reagents.
Infectious or microbial waste:
Warning: handle waste as potentially biohazardous material. Dispose of waste according to accepted laboratory instructions and procedures.
Environmental hazards:
Apply all relevant local disposal regulations to determine the safe disposal.
Safety data sheet available for professional user on request.
For USA: Caution: Federal law restricts this device to sale by or on the order of a physician.
This kit contains components classified as follows in accordance with the Regulation (EC) No. 1272/2008:
|
Warning |
H315 | Causes skin irritation. |
H319 | Causes serious eye irritation. |
Prevention:
P264 | Wash skin thoroughly after handling. |
P280 | Wear protective gloves/ eye protection/ face protection. |
Response:
P302 + P352 | IF ON SKIN: Wash with plenty of water. |
P332 + P313 | If skin irritation occurs: Get medical advice/attention. |
P337 + P313 | If eye irritation persists: Get medical advice/attention. |
P362 + P364 | Take off contaminated clothing and wash it before reuse. |
Product safety labeling follows EU GHS guidance.
Contact phone: all countries: +49-621-7590, USA: 1-800-428-2336
Serum/plasma
For quality control, use control materials as listed in the \"Order information\" section.
In addition, other suitable control material can be used.
Urine
Quantitative urine controls are recommended for routine quality control.
The control intervals and limits should be adapted to each laboratory’s individual requirements. Values obtained should fall within the defined limits. Each laboratory should establish corrective measures to be taken if values fall outside the defined limits.
Follow the applicable government regulations and local guidelines for quality control.
For specimen collection and preparation only use suitable tubes or collection containers.
Only the specimens listed below were tested and found acceptable.
Serum
Plasma: Li‑heparin plasma
The sample types listed were tested with a selection of sample collection tubes that were commercially available at the time of testing, i.e. not all available tubes of all manufacturers were tested.
Chelating anticoagulants such as EDTA, fluoride and oxalate must be avoided.
Sample collection systems from various manufacturers may contain differing materials which could affect the test results in some cases. When processing samples in primary tubes (sample collection systems), follow the instructions of the tube manufacturer.
Centrifuge samples containing precipitates before performing the assay.
See the limitations and interferences section for details about possible sample interferences.
Sample stability claims were established by experimental data by the manufacturer or based on reference literature and only for the temperatures/time frames as stated in the method sheet. It is the responsibility of the individual laboratory to use all available references and/or its own studies to determine specific stability criteria for its laboratory.
Stability in serum/plasma: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 7 days at 15‑25 °C |
7 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
Urine:
Urine samples should be acidified to pH 1 with concentrated HCl to prevent precipitation of magnesium ammonium phosphate. Collect urine samples in metal‑free container.
Stability in urine: LREFUse of Anticoagulants in Diagnostic Laboratory Investigations. WHO Publication WHO/DIL/LAB/99.1 Rev. 2: Jan 2002. | 3 days at 15‑25 °C |
3 days at 2‑8 °C | |
1 year at (-15)‑(-25) °C |
Magnesium Gen.2
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