Genetic testsMost tests look for bits of the virus’ genetic material, and require a nasal swab that is taken by a health professional and then sent to a lab.
This is considered the most accurate way to diagnose an infection, but it’s not perfect: The swab has to get a good enough sample so any virus can be detected.These tests usually take hours to process at the lab so you likely won’t get results back for at least a day, though a handful of rapid tests take about 15 minutes on site.
Other genetic tests use saliva, instead of a swab.Antigen testsA newer type of test looks for proteins found on the surface of the coronavirus, rather than the virus itself.