Which hematoxylin formulation is known for containing aluminum ammonium sulfate?

• A. Harris Hematoxylin
• B. Weigert's Hematoxylin
• C. Gill's Hematoxylin
• D. Ehrlich's Hematoxylin

Answer: (A)

The essential idea is that the mordant used in a hematoxylin formulation defines its chemistry. Aluminum ammonium sulfate acts as the mordant, forming a stable hematoxylin lake that binds to nuclear components and yields a blue-black stain. Harris hematoxylin is specifically formulated with aluminum ammonium sulfate as its mordant, which is why it’s known for containing that compound. Other formulations rely on different mordants or methods (for example, iron-based mordants in some formulations; Ehrlich’s or Gill’s use alternate approaches), so they aren’t defined by aluminum ammonium sulfate.