Histology FAQ

Staining, Histochemistry and Histotechnology

(Frequently Asked Questions)

Dr. John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London, Canada

FAQ Home > Staining Methods, Histochemistry

Iron hematoxylin: ripening not needed

Question.

Why does Bancroft and Stevens tell me to ripen my alcoholic hematoxylin for a month, when the ferric chloride oxidizes it instantly when you combine the two parts?

Answer.

Because B & S is wrong (a very unusual thing in that superb book), and you are right.

For what it's worth, my experiences and occasional experiments fully support the conclusions written in the classical works of Baker, Lillie, Gabe and others. Ferric ions instantly oxidize hematoxylin to hematein and they also form part of the black complex that is retained in cell nuclei.

John Kiernan
London, Canada
(kiernan[AT]uwo.ca)