FIG. 1.

Electrophoretic analysis of EPIYA PCR products. The DNA from H. pylori clinical strains (lanes 1 to 8) was amplified by EPIYA PCR, and the PCR products were analyzed on a 1.5% agarose gel. The samples in lanes 9 to 11 are sequenced EPIYA PCR products from cagA-positive strains with ABCC (lane 9; Hp63, AM292557), ABC (lane 10; Hp5, AM292581), and AB (lane 11; Hp51, AM292592) combinations. Note the ladder-like distribution in the molecular weights of the samples, which is indicative of the presence of multiple repeats. Based on their size, the EPIYA number predictions were 3 (samples 3, 4, 5, and 7), 4 (samples 1 and 8), and 5 (sample 2). Sample 6 was a cagA-negative isolate.