“…The results presented in this study confirm and extend previous reports (Vanderborght et al, 1991(Vanderborght et al, , 1992Cheingsong Popov et al, 1994;Pau et al, 1994;Pinto and Schechter, 1995;Hendry et al, 1996) on specificity of antibody binding to subtype-specific synthetic V3 peptides in that (a) reactivity of Brazilian HIV seropositive plasma with subtype B synthetic peptides is quite high (b) the B%% variant of the B subtype, apparently characteristic of South American HIV-1 strains, can be distinguished from classical B subtype strains by antibody binding assays in the majority of cases and (c) differentiation of B and F subtypes cannot be accomplished by these serotyping assays. The number of D (n= 1) plasma available for this study precludes evaluation.…”