Methods for the detection of HIV-1 antibodies employing polypeptides obtained from gag P6 protein

A method for detecting the presence, or measuring the concentration, of an anti-HIV-1 antibody in a biological sample of a human, wherein said method comprises conducting an immunoassay comprising the steps of:

• (a) contacting said biological sample with a peptide having an epitope that is recognized by said anti-HIV-1 antibody, said contacting being under conditions sufficient to permit said anti-HIV-1 antibody if present in said sample to bind to said epitope and form a peptide-anti-HIV-1 antibody complex;
• (b) contacting said formed peptide-anti-HIV-1 antibody complex with an anti-HIV-1 antibody binding molecule, said contacting being under conditions sufficient to permit said anti-HIV-1 antibody binding molecule to bind to anti-HIV-1 antibody of said formed peptide-anti-HIV-1 antibody complex and form an extended complex;
• said extended complex being immobilized on a solid support;
• and
• (c) removing one or more of unbounded anti-HIV-1 antibody and unbounded anti-HIV-1 antibody binding molecule from said extended complex;
• and
• (d) determining the presence or concentration of said anti-HIV-1 antibody in said biological sample by determining the presence or concentration of said formed extended complex;
• wherein said epitope is present on a peptide comprising SEQ ID NOs.:1 or 6-11 or a peptide consisting of SEQ ID NOs. 2-5 or 141.