Types of Testing

What are the main types of COVID-19 tests?

There are two main types of COVID-19 tests: viral and antibody. 

  • Viral tests include both molecular (also known as nucleic acid amplification tests or “NAATs”) and antigen tests.  Viral tests look for a part of the virus that causes COVID-19.
    • Molecular tests look for the genetic material of the virus. A PCR (polymerase chain reaction) test is simply one type of molecular test.
    • Antigen tests look for proteins that are part of the virus.
  • Antibody tests look for antibodies that the body has made against the virus that causes COVID-19.  Antibody testing is not currently recommended to assess for immunity to COVID-19 following COVID-19 vaccination, or to assess the need for vaccination in an unvaccinated person.  Antibody tests are not “viral” tests since they do not look for parts of the virus. Antibody tests are NOT meant to diagnose current COVID-19 infection.  

You can also use CDC’s COVID-19 Viral Testing Tool to help you understand COVID-19 testing options. The tool helps individuals determine what type of test they should seek. After test results are in, the tool can help interpret test results and guide next steps.

How are specimens collected for COVID-19 tests?

  • For PCR and antigen tests (i.e., viral tests), the most common specimen collected is from the front of the nose.  A small swab is inserted just inside one nostril and rotated a number of times.  Using the same swab, the process is repeated in the other nostril.  For molecular (PCR) tests, a saliva specimen can also be used. 
    • Whether you are collecting the test specimen by yourself at home or at a test site, be sure you wash your hands with soap and water for at least 20 seconds before and after collecting a specimen.  If soap and water are not available, use an alcohol-based hand sanitizer with at least 60% ethanol.  
  • For antibody tests, a blood sample is collected from your arm.

The images below illustrate an anterior nasal specimen collection: