[Histonet] Re: HPS stain

[Robert Richmond]

The hematoxylin-phloxin- saffron stain, which supposedly originated at
the Montreal Neurological Institute, migrated from there to
Columbia-Presbyterian Hospital in New York City, where it was used as
the general oversight stain in surgical pathology at least into the
1960's. When I saw it in use there in 1966 they didn't seem to be
having trouble with it.

On the other side of Central Park, New York Hospital (Cornell Medical
Center) had used a Light Green trichrome stain as a general oversight
stain. I think they abandoned it in favor of H & E after Chandler
Foot's retirement in 1948.

Saffron is a natural dye derived from the stigmas of the saffron
crocus, Crocus sativus. Although it was (and is) extremely expensive,
it was used both as a textile dye and as a spice (in paella, for
example). It's sometimes seen (and smelled) as a component of
expensive curry powders - my wife and I have been experimenting with
Penzey's Maharajah curry powder, which is 2% saffron. The immense hand
labor of extracting all those stigmas from the flowers makes saffron
"the most expensive spice in the world".

Saffron as a histologic dye has traditionally been specified as
"safran du Gâtinais" - from a particular region of France - though I
am not certain that such a product still actually exists. I would
think that any good quality saffron would suffice (don't substitute
safflower, 'dyer's saffron'). You'll pay at least ten dollars a gram
for saffron, at Penzeys anyway.

Some recipes specified as many as seven changes of hot alcohol to
extract the dye, and some people used a reflux condenser for the
extraction. The alcohol extract has a strong medicinal smell which
some people find quite unpleasant.

(I have no connection with Penzeys.com, except that my wife and I have
gotten addicted to their shipments of very high quality spices.)

Bob Richmond
Samurai Pathologist
Knoxville TN