Deletion of Helicobacter pylori vacuolating cytotoxin gene by introduction of directed mutagenesis

Figure 3 PCR amplification for the determination of homolo-gous recombination in Km^r mutant strain. Genomic DNA of NCTC 11638 wild strain and Km^r mutant strain were respec-tively PCR-amplified for the fragments ASm and ASp using the primers ra1 and rs. A single 3.8 kb product ASm was am-plified from Km^r mutant strain as compared with the 3.0 kb product ASp amplified from the wild strain.