Results of patient testing for H. pylori . Results of all testing (including biopsy-based methods and serology) are shown for the thirty-four samples included in the study which gave at least one positive result. Samples 20 and 21 were biopsies collected during endoscopic examinations performed 4 months apart on the same patient. Matched serum samples for this patient were obtained at each visit. Sample 31 was a biopsy collected from the antrum of a patient undergoing endoscopy, while sample 32 was from the body of the stomach of the same patient. Only one serum sample from this patient was received for analysis. The remaining sixty-seven patients (71 samples) were negative for all assays performed (data not shown). The BIOPSY column includes all specimens for which at least one test result was positive (CLOtest, PCR, or histology). The SEROLOGY column includes all serum samples considered reactive by either H. pylori ELISA (IgG and/or IgA), Western Blot (IgG and/or IgA), or both.