Overlapping linear 15-mer and cyclized 15-mer peptides based on gp160 of HIV-1 UG037 and 93MW965 and the overlapping 15-mer peptides of gp41 strain SF162 were synthesized on polypropylene support (minicards), and were tested for reactivity with mAbs as described [49, 50] . Pepscan peptide binding analysis was carried out by an ELISA-based format in which the colored substrate was quantified with a charge-coupled device (CCD)camera and an image processing system. The values mostly ranged from 0 to 3000, a log scale similar to 1 to 3 of a standard 96-well plate ELISA-reader.