[Histonet] Re: Ammonia water pH and other bluing solutions

From:Gayle Callis

You are correct in your concern about losing sections/wrinkling.  Although 
we use a commercial solution, the ideal pH is 8.  We no longer use dilute 
ammonia water, as with higher pH, it is likely the alkaline conditions can 
cause section to fall off the slide.  (hmm isn't this called alkaline 
protein hydrolysis that affects alkaline sensitive protein bonds. Been 
there and had it happen particularly with large, precious difficult to 
obtain decalcified bone sections.

We change the bluing solution DAILY in order to maintain our pH at 
8.  Since water carryover can dilute the bluing solution further after many 
slides are run through, the first of the week fresh change may have correct 
pH but end of week may be entirely different after the watercarry over into 
bluing solution. Bluing solution is cheap. This also goes for dilute acetic 
acid solution after hematoxylin., particularly progressive hematoxylins 
such as Gills, Richard Allen Hematoxylin 1, etc.

An excellent weak alkaline solution is Scotts tap water substitute made 
with salts that are more alkaline in nature.   You can make this up in your 
lab just as easily as ammonia water, but is is much gentler to the 
section.  Daily changes would not be a huge expense.  It is also available 
as a concentrate from various sources, Sigma and Surgipath come to 
mind.  Never lost a section when using this reagent, but ammonia water has 
caused grief in the past.

Gayle Callis
Research Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
PO Box 173610
Bozeman MT 59717-3610
406 994-6367 (lab with voice mail)
406 994-4303 (FAX)

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