We have two types of COVID-19 tests readily available right now. One is an antigen test, and the other is a polymerase chain reaction (PCR) test.
An antigen test looks for particular proteins that exist on the surface of the virus. Its results can be read quickly—usually within minutes—but it can miss some details and is therefore less accurate, and it could produce a “false positive” result.
A PCR test provides additional details, including looking at a small amount of genetic material such as RNA. It can detect very small amounts of the virus, and tests are very specific for COVID-19 versus any other type of coronavirus. Because a PCR test requires specialized equipment and highly trained laboratory professionals to monitor the process, it’s slower and more expensive.
Generally, if a health care provider has ordered a COVID-19 test for you, you’ll be receiving the more accurate PCR test.
As we learn more about COVID-19, antigen tests can become more accurate. Both types of tests are important tools, but it’s important to understand the strengths and weaknesses of each.