RE: PTAH Staining, Zenker etc.

From:"Weems, Joyce" <>

	I'm so glad I'm not a seller of Zenker's without mercury. I surely
wouldn't want the fibres of my rectus abdominis muscle to lose their
striations. I just hate it when that happens! 

	(John, you are too funny) 

	Happy Halloween everybody!!! j

Joyce Weems
Pathology Manager
Saint Joseph's Hospital of Atlanta

	-----Original Message-----
	From:	J. A. Kiernan []
	Sent:	Tuesday, October 31, 2000 12:30 PM
	To:	Histonet
	Subject:	Re: PTAH Staining, Zenker etc.

	On Mon, 30 Oct 2000, Rae Ann Staskiewicz wrote:

	> When we do the PTAH, we mordant in Zenker's which we buy from
	> Supply. It does not contain mercury, instead I believe it is zinc.
	> PTAH still works wonderfully.

	  Zenker's fixative is a chromium-mercury-acetic mixture that was
	  indroduced in 1894, at about the same time as formaldehyde (Blum, 
	  1893) and formaldehyde with zinc chloride (Fish, 1895). At that 
	  time chromium trioxide, potassium dichromate and mercuric chloride

	  had all been used in fixative mixtures for 30 or more years. 

	  The first published substitution of zinc salts (chloride or
	  sulphate) for mercuric chloride in mixtures containing potassium 
	  dichromate may be a short note by  Barszcz,CA (1976): Use of zinc
	  chloride in Zenker-type fixatives. Histo-Logic 6(4), 87.

	    The point I'm trying to make is that if someone is selling a 
	    non-mercury liquid as "Zenker's fluid" he can expect to be 
	    haunted by Zenker's ghost, and may the fibres of his rectus 
	    abdominis muscle lose their striations and become swollen,   
	    amorphous and darkly staining (Zenker's degeneration).

	  Zinc salts and mercuric chloride do not react identically with
	  proteins. otably, zinc chloride or sulphate lowers the pH much 
	  more than mercuric chloride (which is largely unionized in water).

	  Zinc salts probably do not provide the same sub-microscopic 
	  texture of cytoplasmic coagulation as that brought about by 
	  mercuric chloride, but this probably does not matter for most 

	 John A. Kiernan,
	 Department of Anatomy & Cell Biology,
	 The University of Western Ontario,
	 LONDON,  Canada  N6A 5C1


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