COVID-19 rapid testing has similarities to the COVID-19 PCR test, as both tests take swabs from the back of the nose to obtain a mucus sample. Whereas PCR tests look for the virus’s RNA, COVID-19 rapid tests look for proteins located on the surface of the virus that are produced by the virus’s RNA. With COVID-19 rapid testing, also known as antigen testing, the mucus or saliva sample is mixed with a solution that releases the RNA-produced proteins of the SARS-CoV-2 virus. This mixture is then applied to a testing strip containing an antibody that will bind to the proteins if the SARS-CoV-2 virus is present, in which case a visible chemical reaction will occur on the test strip. COVID-19 rapid tests do not need to be sent to a laboratory for analysis, and results for such tests can be returned to the patient within 10 to 15 minutes of the test.