Abstract: A solid-phase immunoassay is provided for determination of HIV antigens in human physiological fluid. The immunoassay is characterized by the coating of a solid substrate with a unique monoclonal antibody which recognizes a common antigenic determinant of a group of HIV core antigens and no HIV envelope antigens of HIV. The test sample preferably also is subjected to a lysing reagent prior to the incubation for uniformly dispersing antigens which may be present in the test sample.

Abstract: A solid-phase immunoassay is provided for determination of members of an immunological pair such as antigen and/or antibody of a single binding pair in human physiological fluid, wherein a single immunoassay enables simultaneous detection of antigen and/or antibody of a single binding pair in a test sample which may have circulating antigen and/or antibody. The immunoassay is characterized by the addition of an amount of antigen or "spike" of the binding pair to the test sample prior to incubation of the test sample in the presence of a solid-phase absorbed antibody of the binding pair. The test sample preferably also is subjected to a lysing reagent prior to the incubation for uniformly dispensing antigens which may be present in the test sample.