There are two types of diagnostic tests for COVID-19: PCR and antigen.
PCR tests detect the virus's genetic material.
- PCR are the most accurate tests for detecting the virus that causes COVID-19.
- They are given with a nasal swab, oral (throat) swab, or by taking a saliva sample.
- PCR tests are used whether or not you have symptoms.
- There are at-home versions and point of care versions, as well as versions analyzed in a laboratory.
- A positive PCR or other molecular amplification test result is considered a confirmed case of COVID-19.
Antigen tests look for the presence of specific proteins found on the surface of the virus.
- Antigen tests typically produce results within 15-30 minutes, more quickly than the PCR test.
- The preferred test to use immediately before attending events where people may not be distancing or wearing masks. It's also preferred for people who need a negative test to go back to work after having COVID-19, or have recently recovered from COVID-19 and suspect that they may be reinfected.
- Antigen tests can identify people who are infectious and could spread COVID-19 to someone else.
- They may not be as accurate, especially for people who do not have symptoms.
- Antigen tests are given with a nasal swab.
- There are at-home antigen tests as well as point of care versions. Some types of antigen tests are analyzed in a laboratory and take longer to get results.
- A positive antigen test result is considered a probable case of COVID-19.
For more information on types of tests, visit the FDA COVID-19 Testing Basics page.