SARS-CoV-2 antigen tests are generally less sensitive than the tests given in the community setting, which are nucleic acid viral tests that use reverse transcription polymerase chain reaction (RT-PCR). Although antigen tests are considered to be highly sensitive and specific to detecting active virus, cases of false positives have been reported.

Because of the risk of false positives, the Delaware Division of Public Health (DPH) recommends using the antigen testing as a screening tool, with confirmatory PCR testing within 48 hours of the positive antigen test.