RECOMMENDATIONS FOR DIAGNOSTIC COVID-19 TESTING:
To evaluate individuals for current infection, a molecular diagnostic test to detect the presence of the virus by polymerase chain reaction (PCR) or other nucleic acid amplification methodology is the gold standard and is the required test type for re-entry into school.
A second method to detect the presence of viral proteins is a diagnostic antigen test. Although these newer diagnostic antigen tests are faster to run, they are less sensitive and less specific and antigen test results must be confirmed by a molecular test.
For more information:
https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/testing.html