Gill hematoxylin is an iron hematoxylin.

• A. True
• B. False
• C. It stains cytoplasm blue
• D. It is used as a nuclear counterstain

Answer: (B)

Gill hematoxylin is not an iron-based hematoxylin. The iron hematoxylins use iron mordants to create the characteristic blue‑black nuclear stain, while Gill hematoxylin uses a non‑iron mordant (often aluminum-based) and is formulated as a nuclear stain that yields blue to blue‑purple nuclei after oxidation. It’s typically used as the primary nuclear stain in a routine H&E protocol, with eosin providing the counterstain for cytoplasm. It does not stain cytoplasm blue, and it is not used as a nuclear counterstain.