Health
Three reasons a negative coronavirus test doesn’t necessarily mean you’re not infected – The Washington Post
Many people are getting tested for the coronavirus before they visit family and friends, but a negative result doesn’t guarantee that you’re not infected.
Coronavirus testing in the United States has ramped up significantly in recent months, with the daily test count hovering around 1.5 million in January. There are two categories of tests: PCR (polymerase chain reaction) tests considered the gold standard and less-accurate antigen tests.
PCR tests use a molecular process and are processed in a lab. Faster and cheaper antigen tests detect proteins on the viruss surface. Most rapid home tests, estimated to be about 90 percent accurate, use the antigen…
