Which stain is used to demonstrate nerve fibers?

• A. Holmes
• B. Cajal
• C. Bielschowsky
• D. PTAH

Answer: (A)

When you want to see nerve fibers, you rely on a stain that deposits silver onto the fine neural processes, making axons and neurofibrils stand out against the surrounding tissue. The Holmes stain is a silver-based method specifically formulated to impregnate these neural fibers, so they appear dark and well delineated. This strong contrast helps you assess the arrangement and integrity of nerve fibers in both central and peripheral tissue, and to spot degenerative changes or tract patterns.

Other options target different tissue components or use different aims. PTAH highlights muscle fibrils and related structures rather than nerve fibers. While some other silver methods can visualize neural elements, the Holmes staining approach is particularly associated with clearly illustrating nerve fibers, which is why it’s the preferred choice here.