[Histonet] gomori methenamin silver

[Bartlett, Jeanine]

We use the Grocott's Method.
 
Stock Solution A: 0.21%  Silver nitrate (2.1 grams silver nitrate with
1000 ml distilled water): make in chemically clean glassware and
refrigerate
Stock Solution B: Methenamine-borax (27.0 grams methenamine, 3.8 grams
borax, 1000 ml distilled water): make in chemically clean glassware and
refrigerate
 
Both stock solutions are stable for up to at least 4 months.  We use
equal portions of each for our working solution.  We do not have a
problem with sediment and the staining is just as good at 4 months as it
is earlier.  We haven't tried it beyond that time period because we
always have it used up by then.  I think the methenamine gives the
silver the alkaline properties needed for a proper reaction.
 
Jeanine Bartlett, HT(ASCP)
Centers for Disease Control
Infectious Disease Pathology Activity
1600 Clifton Road, MS/G-32
Atlanta, GA 30333
 

	-----Original Message-----
	From: histonet-admin <@t> lists.utsouthwestern.edu
[mailto:histonet-admin <@t> lists.utsouthwestern.edu] On Behalf Of Gudrun
Lang
	Sent: Wednesday, December 17, 2003 9:17 AM
	To: Histonetliste
	Subject: [Histonet] gomori methenamin silver
	
	
	Dear histonetters,
	I need help of those, who are familiar to Gomori Methenamin
Silver staining.
	I have troubles to convince my colleages about the advantages of
using a stock meth-silver-solution. (instead of fresh making each time)
	stock:    1:40 10%Silvernitrate : 3% Hexamethenamin (stable for
few months); 
	working:  1:10 Borax : stock
	My colleages think, that the stock solution soon becomes
instable. And that there is a kind of sediment at the bottom of the
bottle (more concentration of silver).
	 
	Can anyone tell me about bad experience with older stock
solutions? What happens, when the stock solution is older than two (or
three,..) months? Is the result of the stain weaker or darker?
	 
	Question 2:
	What is the the function of Hexamethenamin? I know it causes the
high pH, but does it make any compound with the silvernitrate?
	 
	Any help is welcome
	Best wishes from Austria
	 
	Gudrun Lang
	Akh Linz, Austria

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