Well stained sections show blue-black white matter and brown gray matter. This indicates that the sections were inadequately treated with borax-ferricyanide.

• A. Inadequately treated with Borax-Ferricyanide
• B. Overexposed to light
• C. Excessive dehydration
• D. Inadequate fixation

Answer: (A)

Borax-ferricyanide in this staining protocol serves as the developing/differentiating step that brings out the contrast between white matter and gray matter. White matter, rich in myelin, takes on a blue-black color, while gray matter appears brown due to the counterstain. If this developer/differentiator step is not applied adequately, the silver reduction and subsequent differentiation do not proceed properly, leading to insufficient contrast and a brownish gray in gray matter while the white matter stays blue-black. That pattern points to inadequate borax-ferricyanide treatment, rather than other issues like light exposure, dehydration, or fixation problems.