What’s the difference between a PCR and an antigen test?

Molecular (PCR) tests are looking to detect the genetic material inside a SARS-CoV-2 virus particle that causes COVID-19. PCR tests work using a technique called a polymerase chain reaction, which uses a machine to run a series of reactions that convert RNA into DNA, and then make millions of copies of the DNA to magnify it and test it.

Antigen tests, on the other hand, detect proteins — otherwise known as antigens — from the surface of the virus particles in people infected with the coronavirus. For simple strip-based antigen tests, the method is similar to the one used in pregnancy tests that work by mixing the test with a solution that breaks open the virus, freeing specific proteins. The more sophisticated antigen test that AllClear uses utilizes microfluidics to detect the proteins, such as immunofluorescence.