Analyzer Operating Conditions
A: Temperature range of 15-32°C (59-90°F), relative humidity of 15-80% (non-condensing), and altitude ≤ 2,000m (6,500 feet) above sea level.
A: Place the analyzer on a level, vibration free and non-reflective surface; away from direct sunlight. Allow at least 10 cm (4 inches) of space at the rear of the analyzer for airflow. Ensure the vents are not blocked. Allow at least 6 cm (2.5 inches) of space in front of the analyzer for easy barcode scanning. Position the analyzer near a grounded main outlet to avoid creating a trip hazard with the power cable.
A: The cobas Cdiff assay is not CLIA Waived. All other cobas Liat assays are CLIA Waived. A Certificate of Waiver is required to perform this testing in a CLIA Waived setting. To obtain CLIA Waiver information and a Certificate of Waiver, please contact your state health department.
A: Users: Run authorized assays and view assay tube lots. Add assay tube lots. Change own password and badge barcode.
Supervisors: all User permitted actions, plus: review results, manage users (with User or Supervisor roles), set up the analyzer (except network settings), manage assay tube lots, install assays, archive and delete data, export data, import assay tube lots, back up analyzer, manage problem reports, clean USB flash drives.
Administrators: all Supervisor permitted actions, plus: network configuration settings, manage all users, update assays and software, register assays and software, import settings and users, restore analyzer.
A: To connect a laser printer or inkjet printer, the printer must at least support PCL4. Before purchasing a laser printer or inkjet printer, confirm the printer’s PCL within the printer specifications.
Three specific thermal printers and print media are supported and can be connected to the cobas Liat.
For additional information regarding compatible printers, and printer setup, refer to the cobas Liat System User Guide.
Analyzer Maintenance and Cleaning
A: The user is not required to perform any maintenance, other than touch screen calibration.
A: The analyzer does not require service from a Roche service engineer.
Please note that the 5 year maintenance plan is no longer required for systems that have been upgraded to cobas Liat software version 3.3 and higher. If you see a message on your analyzer regarding 5 year maintenance, please contact Roche Liat Technical Support at 1-800-800-5973.
A: Keep the touch screen clean from excessive fingerprints and moisture by gently wiping it with a soft, lint-free cloth. Do not use isopropanol or bleach to clean the touch screen.
A: Do not spray or apply liquid directly on the analyzer or the power supply. Spraying or applying liquid to the analyzer or the power supply may damage the analyzer or pose an electrical hazard.
The exterior of the analyzer and front buttons can be cleaned using a soft, lint-free cloth moistened with either 70% isopropanol or 5-10% bleach solution. If bleach is used, the analyzer must then be wiped twice using a fresh lint-free cloth moistened with 70% isopropanol to remove all bleach residue. Periodically check the rear vent and bottom of the analyzer for excessive dust or debris.
A: Shut down the analyzer. Moisten a lint-free cloth with 70% isopropanol and then gently wipe the outside of the barcode reader window.
Only clean the window of the barcode reader in case of repeated barcode reading failures. DO NOT use bleach to clean the window of the barcode reader.
A: Only use the cleaning tool when prompted by the message “Use cleaning tool” on the screen. Use the provided cleaning tool, following the instructions provided in the Cleaning Tool Guide included with the cleaning tool kit.
DO NOT use the cleaning tool for biological contamination. This tool does not decontaminate the analyzer, but becomes contaminated itself. If you suspect a tube leak happened inside the analyzer, contact Roche Liat Technical Support at 1-800-800-5973.
Reagent Shipping and Storage
A: -20°C to ≤ 35°C (-4°F to 95°F), maximum 5 day transport time
Depending on the season and/or geographic location, ambient gel packs may be added in kit packaging as protection against freezing or excessive heat damage.
Q: What are the appropriate shipping conditions for the cobas Liat Quality Control kits?
A: -20°C to ≤ 45°C (-4°F to 113°F), maximum 5 day transport time for the cobas Cdiff Control Kits
-20°C to ≤ 35°C (-4°F to 95°F), maximum 5 day transport time for all other cobas Liat Control Kits
Q: What are the appropriate storage conditions for the cobas Liat Reagent kits?
A: All cobas Liat reagent kits should be stored at 2-8°C.
Q: What are the appropriate storage conditions for the cobas Liat Quality Control kits?
A: The cobas Cdiff Quality Control kits should be stored at 15-30°C.
All other cobas Liat Quality Control kits should be stored at 2-8°C.
Reagent and Sample Stability
A: Assay tubes are stable until the date of expiration listed on the assay tube package. Do not use reagents beyond their expiration dates. Do not open individual tube packaging until you are ready to perform testing. Store the assay tubes at 2-8ºC.
A: The cobas Cdiff positive and negative controls are stable at 15-30°C until the expiration date indicated on the pouches, regardless of the open date of the pouch.
For all other cobas Liat assays, the positive and negative control tubes contained in factory-sealed pouches are stable at 2-8°C until the expiration date indicated on the pouches. After opening a pouch, controls are stable for 90 days at 2-8°C or until the expiration date, whichever comes first. Write the date opened on the pouch where indicated. Close the zip lock seal on the pouch after each use
A: The cobas Cdiff assay tubes should only be removed from the refrigerator when a sample is ready to be run on the instrument. The sample should be pipetted into the assay tube and run on the instrument without delay.
For all other cobas Liat assays, the assay tube should be removed from the refrigerator when a sample is ready to be run on the instrument. We recommend running the test as soon as possible after the sample is transferred into the assay tube. However, these assay tubes can sit at room temperature for up to 4 hours once the sample has been added.
A: Please refer to the transport and storage section of the relevant cobas Liat assay’s method sheet. All cobas Liat assay method sheets can be found under Documentation and FAQs > Assay Method Sheets.
Assay and Result Information
A: These notches were removed in order to simplify the manufacturing process of the tube frame; this change does not affect the assay performance or functionality.
A: To ensure test accuracy, use only the collection materials indicated in the relevant assay’s method sheet as they have been validated or approved for use with the cobas Liat System. All cobas Liat assay method sheets can be found under Documentation and FAQs > Assay Method Sheets.
Q: Can I view the Ct values from my results?
A: Yes, with system software versions 3.3.1 and higher, the Ct values for positive sample results and positive control results are available in the ResultArchive.csv file. To access this file, archive results to a USB and then open the ResultArchive.csv file in Excel (or other spreadsheet application) to view these Ct values. For detailed instructions on this process, refer to the Quick Reference Guide Opening Result Archive Files with Microsoft Excel.
Additionally, with system software versions 3.3.1 and higher, Ct values for positive sample results and positive control results may be transmitted to connected hosts (DMS/LIS).
A: Yes, we recommend periodically archiving and deleting results and audit trail data from the cobas Liat to maintain optimal analyzer performance. Consider creating and retaining a problem report prior to exporting and deleting data from the analyzer, for any potential troubleshooting needs.
A: The Warning status is generated when the analyzer detects a potential issue, for example with motor movement, and assigns it a code with a low severity rating. A code with a low severity rating is treated as a warning and the instrument attempts a recovery. If the recovery attempt is successful, the script will proceed as intended and the run status Warning is generated on the result report. In this case, the analyzer is performing as intended and the results are valid.
If the recovery attempt is unsuccessful, the severity rating will be escalated, which signals the assay to abort. In this case the analyzer will not give a result and the run status will be Aborted.
A: An assay abort is the premature termination of a sample test. Assay aborts are designed to prevent excessive movements during operation that could result in analyzer damage. Occasional assay aborts are a normal and expected result of this important failsafe. Under normal operation, the analyzer alerts the user if a malfunction or error is detected. Please refer to the Troubleshooting section for information on how to troubleshoot aborts.
A: An invalid is generated when abnormalities in PCR amplification of the internal processing control or assay targets are detected. Invalid results can be expected to occur at a low rate when PCR conditions are not optimal. Please refer to the Troubleshooting section for information on how to troubleshoot invalids.