RE: mast cells

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From:"Hewlett Bryan (CMH)" <HEWLETT@EXCHANGE1.CMH.ON.CA>
To:"''" <>, "'Hedley David Glencross'" <>
Date:Fri, 28 May 1999 09:00:05 -0400
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	It's true that some dye based methods are more rapidly performed,
including the non-metachromatic alcian blue. The superb long toluidine
blue technique of Wingren and Enerback, which is used to unmask GAG's
blocked by formaldehyde fixation, certainly isn't as rapid as IHC. 	
	Are they as good? It depends on the purpose for doing the stain. If
your intent is to quickly check for the presence of mast cells, then
maybe. If you wish to determine whether the number of MC is increased or
decreased, then absolutely not.
	One should consider that there two major sub-populations of mast cell,
which differ considerably in their stainability, depending on the
staining protocol and the fixative used. Connective tissue mast cells
are probably the easiest to stain with traditional dye technology.
Mucosal mast cells can be more problematic, particularly with
formaldehyde fixation. 
The number of mast cells demonstrable varies with the technology used.
In human material, immunohistochemistry for CD117 or Mast cell tryptase
will reveal the greatest number( in rat RMCPI or RMCPII). Dye
technology, independent of fixative, will only stain approximately
60-90% of mast cells ( paper submitted). A simple experiment should
convince you. Stain separate sections from  small bowel with you
favorite dye method and with AA1, perform a mast cell count on the
lamina propria with each stain, the result may astound you.

Valuable insight into the staining of mast cells can be gained from
chapter 24, p695, by Lennart Enerbach. In "Histochemistry in
Pathological Diagnosis". Editor Samuel S. Spicer. 1987. Marcel Dekker
Inc. NY. ISBN 0-8247-7408-6.

I'm sure that mast cell guru John Kiernan will jump in to add his
insightful comments (how about it John?).


>From: 	Hedley David Glencross[]
>Sent: 	May 24, 1999 1:56 PM
>Subject: 	mast cells
>Hi everyone
>I have used AA1 for mast cells myself, and found it good. But I would
>ask, why use ICC (IHC) when metachromatic methods using thionin or
>toluidine blue are just as good and much quicker?
>Yours puzzledly
>Hedley David Glencross

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