Re: PTAH stain
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From: | RSRICHMOND@aol.com |
To: | RHD101@aol.com, Histonet@pathology.swmed.edu |
Reply-To: | |
Date: | Fri, 27 Aug 1999 08:53:05 EDT |
Content-Type: | text/plain; charset="us-ascii" |
Dr. John Shannon asks:
<<Does the PTAH stain have chloroform as one of its ingredients and, if so,
is
there an alternative to the use of chloroform? Are other labs refusing to do
this stain because of the chloroform and its association with liver damage?>>
PTAH (PhosphoTungstic Acid Hematoxylin) prepared in true and ancient form
contains nothing but phosphotungstic acid (phosphowolframic acid) and
hematoxylin. Conceivably someone may have added chloroform as a preservative.
There were formulas that rapidly oxidized the hematoxylin, usually with
permanganate, but the ritual is properly done by leaving the loosely
stoppered bottle in the laboratory window (better on the fire escape) for at
least six months.
PTAH requires primary Zenker fixation, with problems in disposing of both
mercury and chromium. PTA is expensive, and the tungsten may also present
disposal problems. These may all be reasons the reference lab doesn't want to
do the stain.
It's a nice stain for pathologic glia and for muscle striations, but its
chief use - since it took overnight to do - was to give the pathologist time
to think up a name for a weird looking tumor (we didn't have immune stains
back in the Jurassic Period). It was little used thirty years ago, and I
never heard anyone express the blind faith in it expressed by Verdi's Aida
("Omnipotente Ptah!")
Bob Richmond
Samurai Pathologist
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