a test in which a sample is tested in a laboratory (= a place where scientific tests are done) by copying a particular piece of DNA many times so that the DNA can be examined in detail. PCR is an abbreviation for polymerase chain reaction.

If you think you may have COVID-19, you should take a PCR test. 如果您认为自己可能感染了新冠，那应该去做个核酸检测。