The Warhin-Starry technique is used with which fixation?

• A. Formalin fixation
• B. Alcohol fixation
• C. Acetone fixation
• D. Glutaraldehyde fixation

Answer: (A)

Warthin-Starry is a silver staining technique used to visualize certain microorganisms in tissue sections, such as spirochetes and Helicobacter. It relies on preserving tissue structure while still allowing silver to impregnate and deposit around the organisms. Neutral buffered formalin is the preferred fixative because it preserves morphology without masking the argentaffin reactions needed for silver deposition. Alcohol or acetone fixation can alter proteins and extract lipids, leading to weaker or uneven staining, while glutaraldehyde, with its strong cross-linking, can hinder silver impregnation and increase background. Therefore, formalin fixation provides the best balance for reliable Warthin-Starry staining.