Many diagnostic tests for infectious diseases use a technology called polymerase chain reaction (PCR) to determine if a patient is infected with a virus or other pathogen. PCR-based testing works by amplifying a very small amount of genetic material to create millions to billions of copies so that there is enough for it to be detected and analyzed.
PCR testing — particularly when using high throughput instruments — requires far more than just the test itself. There are actually several different consumables required to get to the result, which we break down for you here.
Sample Collection Components: Materials required for collecting a sample from a person’s throat or nose:
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Nasal swab used to collect the sample by a healthcare provide. Sample collection swabs are designed specifically to be used for PCR testing and differ from household cotton swabs such as Q-tips |
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Testing tube containing a solution called viral transport media that protects the integrity of the sample within the tube during transport to the lab |
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Common laboratory tool known as a pipette used to transfer the sample from the collection tube into a secondary tube where it will be readied for analyzation with other patient samples. Note that not all samples need to be pipetted, as this depends on the type of test. |
Test-Specific Components: Ready-to-use test kits that include all the components needed to extract the RNA from the patient sample and optimize it for PCR. Each kit includes:
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A premixed solution, called a PCR master mix, that contains a complex blend of biochemicals, called reagents, and other components necessary to run the PCR test |
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Essential compounds to multiply and amplify the genetic material |
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Positive and negative controls that are run with every batch to ensure the test is functioning properly |
Non-Specific Test Components: Also known as omni reagents because they are test agnostic
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Manufacturer-specific racks for holding sample tubes, pipette tips to transfer samples onto processing and amplification plates. Up to 96 samples can be processed on a single plate |
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Manufacturer-specific chemicals that are typically kept readily available in labs as they are used for many kinds of tests used to detect pathogens – from HIV to the human papillomavirus (HPV) to SARS-CoV-2. They are used to prepare the sample for analysis by breaking open the cell, extracting the RNA and purifying it |
