Which tissue is considered an excellent control when validating the Weil staining technique?

• A. Spinal cord
• B. Cerebral cortex
• C. Hippocampus
• D. Cerebellum

Answer: (A)

Weil staining is used to visualize nerve fibers and myelin with silver impregnation. To validate this technique, you need a tissue that presents abundant, well-organized myelinated fibers so the staining pattern is clear and reproducible. The spinal cord provides exactly that: its white matter contains extensive, neatly arranged myelinated tracts, giving a strong, uniform staining result that serves as a reliable positive control. This makes it the best tissue for confirming the staining works before applying the method to other tissues.

Tissues like the cerebral cortex, hippocampus, or cerebellum have more complex architectures and varying fiber content, often with less uniform myelination. While they can show staining, they don’t offer the same straightforward, consistent standard for validating the technique as spinal cord white matter does.