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.

Molecular tests are far superior to rapid antigen tests—and now you can get them for home use. Amanda Blum is a freelancer who writes about smart home technology, gardening, and food preservation.

Every American traveling abroad needs to take an antigen test to return to the United States. But the start of the trip is often even more cumbersome, as many other countries (nearly every one I have ...

Recall, if you dare, life in December 2020. America had just approved Covid-19 vaccines for use, but most of us wouldn’t get a shot for months. Instead, amid the second surge of coronavirus cases, ...