What is a PCR test for COVID-19?

What is a COVID-19 PCR Test

A COVID-19 PCR test detects the genetic material (known as RNA) that is specific to the SARS-CoV-2 virus.  It is a highly sensitive test that can detect the presence of the virus within days of an infection.

PCR stands for Polymerase Chain Reaction.  This is the laboratory technique used to copy or amplify the genetic material in a sample many times to aid its detection.  It is this amplification process which makes the test very sensitive, allowing it to detect the low levels of virus present at the start of an infection.

The PCR test is also sometimes called an antigen test (because it is detecting the virus itself, rather than the body’s antibodies produced in response to the virus) and is considered the ‘gold standard’ test for SARS-CoV-2 detection.

A combined swab sample is taken from the back of the throat and the nasal passage which is then sent to the Cellmark laboratory in a viral inactivation buffer for testing.  Results are normally provided within 12 – 24 hours.  The PCR test used at Cellmark is the same type of test that is used by Public Health England to test members of the public who are displaying symptoms of the disease.