FIG. 3.

DHC PCR sensitivity assay. (A) PCR dose-response assay of serially diluted Victoria Dehalococcoides 16S rDNA plasmid DNA, performed with Dehalococcoides group primers Fp DHC 586 and Rp DHC 1090. The two outside gel lanes are molecular weight markers (Gibco BRL 1-kb ladder); the eight left interior lanes, PCR performed on serial diluted plasmid copies (10⁷ to 10⁰) per 50-μl reaction. The rightmost interior lane is a PCR control with no plasmid template (0). (B) PCR dose-response assay in ethidium bromide-stained gels: graph of the pixel densities in gel panel A for the PCR products, as determined by the NIH Image 1.62 program, and the numbers of copies of cloned Victoria Dehalococcoides 16S rDNA sequences in 50-μl PCR mixtures.