CDC recommends collecting and testing a single upper respiratory swab from the nostril. This sample is then processed. Using a technique called real-time reverse transcriptase (RT)-polymerase chain reaction (PCR), the test can detect the COVID-19 virus RNA genome. In practice, coronaviruses need to replicate a reasonable amount in order for there to be enough genetic material that can be used for the test.

Drafted: 16 March 2020