PCR (polymerase chain reaction) tests have been designed to find genetic material called RNA that tells the virus to make these proteins. This test the most accurate Covid-19 test. When swabs are taken for PCR tests, reagents are used to convert the RNA into DNA in order to identify any infection within the patient. Antigen tests have been designed to find proteins on the surface of the virus to identify the pathogen. Antigen tests are often called rapid tests and are carried out by mixing the sample with a solution where it releases the viral proteins. The combination is normally applied on a paper strip that will be able to detect any antibodies that bind the protein.