Purified by immunoaffinity chromatography to ≥ 95% purity as determined by SDS-PAGE, reduced. Peroxidase conjugated rgp120 HIV-1 IIIB (Baculovirus). Molar Ratio: 2-4 peroxidase molecules per molecule of gp120. Specificity: Peroxidase conjugated rgp120 IIIB binds to murine monoclonal antibodies of defined epitope specificity and human monoclonal/polyclonal antibodies in ELISA and Western ELISA. Biological Activity: Peroxidase conjugated rgp120 IIIB binds to immobilized human T-cell receptor CD4 in ELISA and Western ELISA. Applications: A dose dependent response assay should be performed to determine the optimal concentration for use in specific applications. 1. ELISA and Western ELISA may be performed at dilutions of 1:1000 range depending on the concentration of CD4 in the test system. Binding to murine and human monoclonal/polyclonal antibodies may be performed at higher dilutions.