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 widely shared claim on social media has brought the Centers for Disease Control and Prevention's decision to retire its PCR test for COVID-19 back into the spotlight. "CDC Withdraws Use of PCR Test ...

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.

The government is offering another round of free at-home COVID tests to Americans in time for the holiday season. As flu and RSV season kick into full swing, precautions meant to keep families healthy ...