PCR tests, also called molecular tests or nucleic acid tests, are considered the gold standard in detecting the presence of SARS-CoV-2, the virus that gives rise to COVID-19. However, they can take a few days to process, resulting in unnecessary quarantine for negative individuals or delays for those who require proof of negative testing for travel or other commitments. Rapid antigen-detecting tests, on the other hand, are convenient, but less reliable than PCR tests.