COVID-19 diagnostic testing is done to find out if you're currently infected with SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19).The U.S. Food and Drug Administration (FDA) approved these types of tests for diagnosing a COVID-19 infection:PCR test. Also called a molecular test, this COVID-19 test detects genetic material of the virus using a lab technique called polymerase chain reaction (PCR). A fluid sample is collected by inserting a long nasal swab (nasopharyngeal swab) into your nostril and taking fluid from the back of your nose or by using a shorter nasal swab (mid-turbinate swab) to get a sample.