The problem shown in the image could be corrected best by which action?

• A. Removing the cover slip and decolorizing and restaining the section
• B. Increasing the time in hematoxylin
• C. Using older mounting medium
• D. Extending dehydration steps

Answer: (A)

When staining isn’t giving reliable, interpretable color, resetting the stain from scratch is often the most effective fix. Removing the cover slip and decolorizing, then restaining allows you to clear out old mounting medium and any overstaining or uneven development that has occurred, giving you a clean slate to reapply the stain correctly. By unmounting, you remove barriers that can obscure color development or trap artifacts under the coverslip, and the tissue can be rehydrated and re-stained so nuclei and cytoplasm achieve proper differential coloring again. The result is crisper, more diagnostic contrast because you’re starting with a fresh stain on a properly prepared slide.

Extending dehydration or using older mounting medium won’t address the underlying staining imbalance and can introduce new artifacts, while simply increasing time in hematoxylin risks over- or under-staining rather than restoring the correct contrast.