On Mar. 2, 1985, the FDA announced the approval of the Abbott first antibody test kit to screen blood donors for HIV-1, the virus that was responsible for the vast majority of AIDS cases in the U.S. The test was designed to screen blood products, not to diagnose AIDS.

The first-generation assays detected IgG antibody and became positive 6 to 12 weeks postinfection. False-positive results occurred, and, a two-test algorithm was developed using a Western blot or immunofluorescence test as a confirmatory procedure.