Abstract: The invention provides peptides having immunological properties in common with the backbone of an immunodominant region of the transmembrane envelope protein of mammalian immunodeficiency viruses, which region comprises a disulphide loop and which region is unexpectedly highly conserved in mammalian immunodeficiency viruses derived from different mammalian sources. The invention also provides method and immunoassay test kits for detection of mammalian immunodeficiency viruses using these above peptides. The invention also relates to antibodies directed against the above peptides, and their use in immunoassays and as immunoadsorbents for mammalian immunodeficiency virus.

Abstract: The assay off the present Invention is of particular use for detecting drugs, hormones, steroids, antibodies and other molecules circulating in the blood of a mammal or other animal.

Abstract: In an erythrocyte agglutination assay, the agglutination reagent comprises at least one erythrocyte binding molecule coupled to at least one specific analyte binding molecule wherein the erythrocyte binding molecule does not cause agglutination when incubated with erythrocytes in the absence of analyte. Preferably, the erythrocytes are endogenous to the blood sample to be tested, that is, a whole blood sample is assayed. Mixtures of conjugates and conjugates of analyte analogues with erythrocyte binding molecules may also be used as agglutination reagents. The reagents and their use in direct or indirect assays is disclosed.