HOW DO THESE TESTS WORK? Both PCR and rapid antigen tests use samples obtained from nasal and/or throat swabs to detect the presence of the virus. However, what they are looking for is different.

One of the best ways to figure out how far a virus like COVID-19 has spread in a community is to test for it. This step-by-step guide explains how coronavirus swab-the-nose-and-throat tests work ...