A PCR test, or polymerase chain reaction test, is a molecular test that detects genetic material from a specific organism, such as a virus. The PCR test is a highly accurate and reliable test that analyzes a sample from the upper respiratory tract to detect the presence of genetic material (RNA) of SARS-CoV-2, the virus that causes COVID-19. The test works by amplifying small amounts of RNA from specimens into DNA, which is replicated until SARS-CoV-2 is detectable if present. The PCR test is the gold standard test for diagnosing COVID-19 since it was authorized for use in February 2020. The test can detect the virus even in the earliest stages of infection, making it highly sensitive and accurate. PCR tests require a skilled laboratory technician and special equipment to run them, and the amplification process can take an hour or more from start to finish. PCR tests are more reliable and accurate than antigen tests, which are also used to diagnose COVID-19, but antigen tests produce faster results.