A P-value of < 0.05 was considered statistically significant. We compared the accuracy

of TPAg EIA and Rapid TPAg by testing 111 fecal samples from patients with gastrointestinal diseases. As shown in Table 1, the accuracy of TPAg EIA and Rapid TPAg was 100% in 58 H. pylori-positive patients and 53 H. pylori-negative patients. To evaluate the sensitivity FK228 mw and specificity of TPAg EIA and Rapid TPAg, we examined the following samples using both the kits: H. pylori ATCC 43504, 1344 or 485 H. pylori clinical strains, four Helicobacter species (H. hepaticus, H. felis, H. mustelae, and H. cinaedi), and five intestinal bacteria (C. jejuni, E. coli, B. vulgatus, B. breve, and B. infantis). As shown in Figure 2 and Table 2, both TPAg EIA and Rapid TPAg showed no cross-reactivity to antigens of other Helicobacter species or the intestinal bacteria. Accordingly, the specificity of both TPAg EIA and Rapid TPAg was 100%. As shown in Table 3, 1342 of 1344 clinical strains tested positive by TPAg EIA and 483 of 485 clinical strains

tested positive by Rapid TPAg, resulting in sensitivity of 99.9% and 99.6%, respectively. TPAg EIA and Rapid TPAg showed negative results in the same H. pylori isolates. The detection limits of the H. pylori ATCC 43504 antigen by TPAg EIA and Rapid TPAg were 37.5 and 100 ng/mL, respectively. The detectable concentration of the antigen JQ1 was estimated to be corresponding to 105 CFU of the cells/mL in the collection device. The absorbance values of TPAg EIA (y-axis) and the catalase activity (x-axis) of 127 H. pylori clinical strains were plotted in Figure 3. The results indicate that the catalase activity was highly correlated with the absorbance value (R2 = 0.8356, P < 0.01). This result suggests that the absorbance of TPAg EIA would reflect the catalase activity. Two strains with no absorbance with TPAg EIA showed slight catalase activity (less than 2 mmol/min/mg). We

examined the diagnostic performances of TPAg EIA and Rapid TPAg stored under the following conditions: TPAg EIA at 4°C and Rapid TPAg at 30°C for BCKDHA 12 months in the presence of desiccant. The diagnostic performances of both TPAg EIA and Rapid TPAg were examined using H. pylori ATCC 43504 antigen (n = 3) every 3 months. As shown in Figure 4 (TPAg EIA) and Table 4 (Rapid TPAg), the results indicate that both test kits could be stored for 12 months. The absorbance value of TPAg EIA was slightly decreased between 3 and 12 months when the antigen concentration was 300 ng/mL, but the diagnostic performance was not hindered during the 12 months. The diagnostic performance of Rapid TPAg indicated that it could be kept through long storage periods when the H. pylori antigen was applied at 37.5, 100, and 300 ng/mL. The Rapid TPAg was a very stable diagnostic reagent even when it was stored at 30°C.