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 false positive result is possible with a rapid COVID-19 test. It happens when a person does not have COVID-19 but still tests positive for the disease. People can use a rapid COVID-19 test at home ...
In early January, more than 700 Stanford University athletes took rapid Covid tests upon returning to the campus. Those who tested negative — and some who tested positive — were also given PCR tests.