PSR(РТ-ПЦР; polymerase chain reaction (PCR): A PCR test for COVID-19 is a test used to diagnosis people who are currently infected with SARS-CoV-2, which is the coronavirus that causes COVID-19. The PCR test is the "gold standard" test for diagnosing COVID-19 because it's the most accurate and reliable test.clevelandclinic.orgTatiana Okunskaya)