Phenotypic Assay
A laboratory test that determines by direct experiment whether a particular strain of HIV is resistant to anti-HIV drugs. This is different from a genotypic assay, which uses an indirect method to find out if a particular strain of HIV has specific genetic mutations that are associated with drug resistance.
See Also: Resistance Testing, Genotypic Assay
Source:
AIDSinfo, U.S. Department of Health and Human Services (DHHS)