Figure 1From: Pathogenicity island cag, vacA and IS605 genotypes in Mexican strains of Helicobacter pylori associated with peptic ulcersDetection of the cagA gene by Southern blot hybridization. (A) Hybridization for 50 genomic DNA of the isolates and 4 H. pylori reference strains as positive and negative controls, as well as a control the plasmid with the intra-cagA gene cloned, and distilled water as an internal-reaction negative control. (B) Schematic representation of the result of hybridization: circles continuous and discontinuous for positive and negative hybridization, respectively. Abbreviations: CTLS, controls; NPU, non-peptic ulcers; NBPU, non-bleeding peptic ulcers, and BPU, bleeding peptic ulcers.Back to article page