COVID-19 And PCR Testing - Cleveland Clinic

A PCR (polymerase chain reaction) test is a way to look for genetic material (DNA or RNA). After taking a body fluid sample (like blood) or a swab from a body site (like deep in your nose), scientists use PCR to make many copies of DNA (amplification) that was in the original sample. By amplifying with PCR, scientists can better analyze the DNA or RNA that was in the original sample.

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There are many PCR tests. Each is different and is designed for a certain purpose. For example, some PCR tests can determine if a specific virus is present in the sample, which might be making you sick. Other PCR tests can determine if certain genes in your body might have important changes.

Most of us know the term “PCR test” because of testing for COVID-19. But it’s been used in medicine for a long time and has many other uses. Any test that uses a polymerase chain reaction technique is a PCR test. PCR is a type of nucleic acid amplification test (NAAT).

What is a COVID-19 PCR test?

Healthcare providers can use a PCR test to determine whether you have a COVID infection. They use a swab to get a sample of mucus or secretions from deep in your nose. PCR is then used to determine if genetic material (RNA) of SARS-CoV-2 (the virus that causes COVID) in your sample.

What can PCR detect?

Healthcare professionals perform PCR tests for many reasons. PCR can diagnose or detect:

• Infectious diseases (viruses, bacteria, fungi and parasites)
• Genetic diseases, like cystic fibrosis, Huntington’s disease, fragile X syndrome and others
• Types of cancer, like lymphoma
• Gene changes (variations) in cancer that can be targeted with specific medications.
• Gene changes that can put you at higher risk for certain diseases (like genetic testing for cancer risk)
• Gene changes in prenatal testing

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Forensic labs can also use PCR to create detectable amounts of DNA found at crime scenes.