Types of COVID-19 Tests | FastLab

Viral tests, sometimes called diagnostic tests, can detect if you have SARS-CoV-2, the virus that causes COVID-19. There are two types of diagnostic tests: molecular and antigen.

If you have questions about which test is right for you, talk to a health care provider.

A positive viral COVID-19 test result (molecular or antigen test) means that the person who was tested has COVID-19 and can spread it to others. If you get a positive test result, you should stay home and away from others. This advice does not change if you get a second test that is negative. See the section If You Are Sick or Test Positive: COVID-19.

It is generally not recommended that people be tested again after getting a positive result. However, individuals working in healthcare and long-term care settings should follow testing recommendations specific to those settings. See Health Advisory: Antigen-based testing for SARS-CoV-2 (PDF).

Molecular Testing

PCR, nucleic acid amplification tests (NAATs), and other molecular amplification tests detect the genetic material of the virus.

Molecular tests are the most accurate tests for detecting the virus that causes COVID-19.

They can be used whether or not you have symptoms.

They are performed with a nasal swab, oral (throat) swab, or by taking a saliva sample.

Nasal swab: A nasal swab looks like a long swab. It is inserted about two inches into the nose and swirled for a few seconds. The swab is removed and sent to the laboratory for analysis. Nasal swabs are quick and accurate and are a good choice for most people. You may experience a tickling sensation while the swab is in your nose, and after the swab is removed, you may sneeze or have watery eyes for a moment or two. Health care providers are more likely to use nasal swabs that penetrate further into the nasal cavity, and you may feel more discomfort than when performing a nasal swab at home.

Saliva test: Saliva tests are self-administered; this means that after you are shown how to perform the test, you will do it yourself. You will spit several times into a funnel attached to a tube and then screw in a cap to complete the test. If you are at a community testing center, you will give the sample to a proctor; if you test at home, you will put the sample in a prepaid UPS envelope and mail it. Most people need 10 to 12 minutes to produce enough saliva to fill the tube. Saliva tests are more convenient than nasal swabs and just as accurate, but may not be a good option for those with low saliva production, such as very young children or those who have had a stroke.

A positive PCR, NAAT, or other molecular amplification test result is considered a confirmed case of COVID-19.

Antigen testing

Antigen testing, sometimes called rapid testing, looks for specific proteins on the surface of the virus.

Antigen tests produce results more quickly than other tests.

They are performed with a nasal swab.

A positive antigen test result means the person has COVID-19.

For more information on rapid tests that can be performed at home, visit COVID-19 Self-Testing.