Fig. (1) Heteroduplex mobility assay of “nag 1” for env (C2-V3) and gag (p24-p7) genes. Heteroduplex and homoduplex bands are indicated in the figure. The lanes are marked according to subtype specific references. The heteroduplex with subtype B reference amplicons (B2) exhibits the fastest mobility as compared to subtype C reference amplicons (C1, C2, C3, C4) in case of env gene. For gag gene, the heteroduplex with subtype C reference amplicons (C1, C2, and C3) exhibits the fastest mobility as compared to subtype B (B1) and subtype A (A1) reference amplicons.