DGGE profile from amplifications of equal amounts of template DNA from paired isolates.
Lanes 1–5: Amplicons of isolates amplified individually included to identify migration position of isolate-specific bands as labeled. Pairwise amplifications in lanes 6–13: 6, 70-2 and M22; 7, 70-2 and 50; 8, M22 and 50; 9, M22 and M16; 10, 50 and M16; 11, M22 and 35; 12, 50 and 35; 13, M16 and 35; B, blank. Nonspecific bands in the upper portion of the gel in lanes 6–13 are presumed to be heteroduplexes formed as a result of the reannealing of similar, but nonidentical single-stranded products.