I do many Movats. I make my alkaline alcohol w/ 90ml 95% ETOH and add 10
ml ammonium hydroxide. I do not worry about pH.

Betsy Molinari HT (ASCP)
Texas Heart Institute
Cardiovascular Pathology
6770 Bertner Ave.
Houston,TX 77030
832-355-6524
832-355-6812 (fax)


-----Original Message-----
From: histonet-bounces@lists.utsouthwestern.edu
[mailto:histonet-bounces@lists.utsouthwestern.edu] On Behalf Of Monfils,
Paul
Sent: Tuesday, November 29, 2005 12:52 PM
To: histonet@lists.utsouthwestern.edu
Subject: [Histonet] Movat's Pentachrome question

Does anyone do Movat's Pentachrome stain?  I have a researcher who wants
to
do it.  My question involves the "alkaline alcohol" the procedure calls
for.
The protocol says to add ammonium hydroxide drop by drop to 95% ethanol
until the pH reaches 8.0 or higher.

Question 1, a theoretical one - How can you accurately measure pH in a
nearly water-free solution?  Presumably an ionic compound would not
ionize
very well in such a solution?

Question 2, a practical one - When I put the pH probe into 95% ethanol,
the
meter already reads higher than 9.0, even without adding any ammonium
hydroxide. Is this your experience?

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