Sheehan and Hrapchak dissolve hemtoxylin in water, then "added
ingredients", nothing about order although I would assume the order is as
written on list of chemicals.  Carson dissolved hematoxylin in water,
heated to boiling for 5 min, added iodate first, ripened 10 min, the added
other ingredients in order, alum salt, citric acid and chloral hydrate.

To get a better handle on the chemistry of alum hematoxylins, I strongly
recommend your students read "Harris Hematoxylin,", What Harris really
wrote and the mechanism of hemalum stains, Meloan and Puchtler, JOH,
10(47):257-261, 1987.  

This article changed the way I think about alum hematoxylin staining,
discussed the role of acids, etc.  It also explains the role of the alum
salts, oxidizers, etc.  

Harris loved Mayer's formulation, and also used his own "Harris"
formulation as a progressive hematoxylin stain.






Gayle Callis
Veterinary Molecular Biology
Montana State University
Bozeman MT 59717-3610
406 994-4705
406 994-4303