What are the expected color results for the Steiner stain?

• A. Spirochetes, Campylobacter pylori, and Legionella appear dark brown to black; background is light yellow
• B. All structures blue
• C. Background pink
• D. Green background with black structures

Answer: (A)

Steiner stain is a silver-based method used to visualize spirochetes in tissue. The silver deposits onto the slender spirochete organisms during development, so they appear dark brown to black. The surrounding tissue is counterstained to produce a light yellow background, creating a high-contrast view where the spirochetes clearly stand out. This staining pattern—dark, metallic spirochetes against a pale yellow background—is what makes the Steiner stain distinctive.