FIG. 3.
Representative example of an HTA. Radioactively labeled single-stranded probe was prepared from HIV-c-puroNL4-3 plasmid DNA by asymmetric PCR using the segment 8 primer pair (lane ss). Radioactively labeled double-stranded segment was amplified at the same time as a control (lane ds). Segment 8 is 612 bp in length. The sequence difference between the two strains within this segment is approximately 1%. The probe was annealed with PCR products amplified from NL-c-puroNL4-3 (lane N, homoduplex control), HIV-gptHXB2 (lane H, heteroduplex control), or genomic DNA from different target cell clones (clones 736 to 738, 740, 743 to 746, and 748 to 751). Clones 738 and 748 are shifted compared to the band for HIV-c-puroNL4-3 DNA and were therefore scored as recombinants. Symbols: +, band shifted due to heteroduplex formation; −, nonshift homoduplex band.