Dear Gerald,
if you want a strong Haematoxylin with the same dye content as Harris and
non-toxic to boot, then try Lillie-Mayer Haematoxylin. The recipe is in
"Histologic Technic & Practical Histochemistry" 4th Ed. by Prof.RD Lillie
and Harold Fulmer p.2004-208. This text is of such bibical proportions and
trivia inclusions that it is a must for every Histo Lab, and despite it's
age is ever appropriate.
It has up to a five year shelf life esp. if you only use Sodium Iodate at
the rate of 0.2g/Litre. The incorporation of Glycerol as a stabiliser also
prevents further oxidation and acts as an antifreeze as well.The
incorporation of Glacial acetic acid is something you will have to control
or even eliminate depending upon how regressive you wish to use the stain,
and also depending upon what additional structures you wish to demonstrate
viz. Mucin and elastin. The recipe instructions emphasise that heat must not
be used- so you have a winner! Besides which when you plunge your flask of
boiling harris into water you always run the risk of loosing the lot with a
heat stress fracture, not to mention the risk of cutting or burning
yourself.
Merck Aust. also market a Non-toxic Harris Haematoxylin that performs
similarly.
Hope this is of practical use to you,
Regards Mike Rentsch (Victoria)