List of recombinant proteins and peptides derived from subtype-A, B and C HIV-1 viruses, NA: Not applicable. 2 Four anti-V3 antibodies, three from Indian I (277, 903 and 904) and one from American A (447-52D) HIV-1 infected donor were tested for their relative binding. The binding activity of anti-V3 mAbs against proteins and peptides was tested by ELISA using mAbs at a concentration ranging from 10 to 0.00003 μg/ml (12 dilutions). The 50% binding titers (Max50, conc. μg/ml) of each antibody against the corresponding protein or peptide is depicted as numerical values in Bold (high affinity), Italic (low affinity) and >10, where Max50 value was not reached. Human anti-parvovirus B19 mAb 1418 was used as negative control. Each experiment was performed at least two independent times. Amino acid sequences of linear overlapping peptides encompassing the third variable region (V3: Underlined (middle)), flanked by second (C2: (left)) and third (C3: (right)) constant regions and are aligned with the corresponding consensus-C gp120 sequence. 2 Four anti-V3 antibodies, three from Indian I (277, 903 and 904) and one from American A (447-52D) HIV-1 infected donor were tested for their binding to overlapping peptides by ELISA using mAbs at a concentration ranging from 10 to 0.00003 μg/ml (12 dilutions). The 50% binding titers (Max50, conc. μg/ml) of each antibody against the corresponding peptides is depicted as numerical values in Bold (high affinity), Italic (low affinity) and >10, where Max50 value was not reached. Human anti-parvovirus B19 mAb 1418 was used as negative control. Each experiment was performed at least two independent times.