Polymerase chain reaction (PCR) and rapid (antigen) tests for COVID-19 both involve taking a swab. Results for a PCR test take longer, as it needs to go to a laboratory. It is more costly but tends to ...

A polymerase chain reaction (PCR) test detects genetic material from a pathogen or abnormal cell sample. Ways of collecting samples include a nasal swab, a saliva swab, or taking a sample of blood.

With Omicron surging in the United States, many people are taking COVID-19 tests to see whether they test positive. Most people will take either a rapid antigen or PCR test. Though the PCR test is ...