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 ...

Polymerase chain reaction (PCR) tests are one of the most popular diagnostic tools for the detection and diagnosis of viral diseases, such as coronavirus (COVID-19), due to their ability to rapidly ...