A RAPID ANTIVIRAL IN-SITU ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR FELINE IMMUNODEFICIENCY VIRUS

An in situ enzyme-linked immunosorbent assay (ELISA) was developed as a rapid alternative to the focal infectivity assay (FIA) for screening potential anti-retroviral molecules. The assay utilizes 96-well micro titer plates to allow for determination of antiviral effect and cytoto xicity of multiple compounds simultaneously. In contrast to the FIA wh ich requires visual scoring of foci under low-power microscopy, the 96 -well ELISA is read spectrophotometrically based on the soluble alkali ne phosphatase substrate, p-nitrophenyl phosphate. The IC50 and CC50 v alues for several antiretroviral compounds were determined using the E LISA and results were confirmed by FIA. In all cases, compounds assaye d by the newly described ELISA exhibited IC50 values in agreement with literature values derived from either the FIA or reverse transcriptas e assays.