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 Centers for Disease Prevention and Control, or CDC, tweeted that "there’s a 10% chance" that people’s PCR tests were sent to laboratories across the country for genomic sequencing analysis.

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 ...

This decision, well within current norms for care, was nonetheless consequential: The president was forced to cancel a trip to advocate for legislation in support of the domestic semiconductor ...