A modified McMullen's staining for Helicobacter pylori: A high-contrast, visibly prominent method

Background. Many stains can be used for the histological assessment of Helicobacter pylori, but all have defects from the standpoint of sensitivity, convenience, stability, visible prominence and cost. This paper describes a stain which produces satisfactory results on all the above accounts. Materials and Methods. Paraffin-embedded sections were dewaxed and treated with 0.2% w/v carbol fuchsin for two min; then 1.0% w/v malachite green was applied for two minutes. Results. This technique stained the bacterial form a deep magenta against a light green background. The characteristic morphology of H. pylori was identified very easily as a stumpy curved rod, and the coccoid forms were also identified. Staining was not specific with mixed samples of bacteria, but it was sufficient to identify H. pylori in the gastric mucosa. Conclusion. We have established an easy, stable, convenient, low-cost, and easily recognizable staining method for H. pylori in paraffin-embedded tissue.