Diff-Quik Giemsa modification is commonly used to detect which organism in tissue?

• A. Helicobacter pylori
• B. Mycobacterium tuberculosis
• C. Plasmodium falciparum
• D. Candida albicans

Answer: (A)

Diff-Quik with a Giemsa modification is used on tissue sections to visualize certain microorganisms that reside on the mucosal surface. In gastric biopsies, Helicobacter pylori appear as slender curved Gram-negative rods along the surface epithelium, and the Giemsa modification stains them dark blue to purple, making them stand out against the surrounding pink-orange tissue. This staining helps confirm H. pylori infection directly in the biopsy specimen.

Other organisms mentioned are typically identified with different stains or in different specimen types: Mycobacterium tuberculosis is usually detected with acid-fast stains like Ziehl-Neelsen; Plasmodium falciparum is most commonly found in blood smears stained with Giemsa; Candida albicans is often highlighted with special fungal stains such as PAS or Gomori methenamine silver.