Which chemical is associated with the stabilization of hematoxylin solutions?

• A. Ferric chloride
• B. Ammonium aluminum sulfate
• C. Sodium chloride
• D. Acetic acid

Answer: (B)

Stabilizing hematoxylin solutions relies on forming a durable complex with a mordant. Ammonium aluminum sulfate provides aluminum ions that bind to hematoxylin, creating a hematoxylin–aluminum complex that remains colorfast on tissue. This stabilization keeps the characteristic blue stain consistent during differentiation and counterstaining, improving reproducibility across slides. Ferric chloride is involved in advancing hematoxylin to its active form (hematein) in some protocols but does not serve to stabilize the dye solution. Sodium chloride and acetic acid influence staining behavior or acidity, but they do not provide the stabilizing mordant effect that ammonium aluminum sulfate does.