Diagnostic testing for coronavirus infection is currently done through a nasal or throat swab. A clinician uses a long cotton swab to take a sample of mucus and other secretions from the back of your throat. The swab enters through the patient's nose and passes into your throat. This sample is sent to a laboratory for testing. The lab will perform a polymerase chain reaction, or PCR, test, which uses extracted genetic viral material from the sample, to confirm a COVID-19 diagnosis