Detection of Helicobacter pylori in paraffin-embedded and in shock-frozen gastric biopsy samples by fluorescent in situ hybridization.

We report on the successful application of fluorescent in situ hybridization for detection of Helicobacter pylori and determination of its clarithromycin susceptibility in formalin-fixed and paraffin-embedded gastric biopsy specimens that had been prepared for pathological examination. This method is useful when results from conventional culturing with antibiotic susceptibility testing are not available.