Re: [Histonet] Alcian Blue-Metanil Yellow

From:John Kiernan

   I  haven't  used  the  combination  but have used both these dyes in
   other  =  combinations.  Both  dyes are prone to deterioration, as
   outlined   belo=  w.
Solutions of metanil yellow don't keep v= ery well - the colour slowly changes to light brown over a couple of wee= ks or so, and then you need to make a new solution. Could deteriorat= ed metanil yellow be the cause of your difficulty?
 <= BR>Even the best alcian blue can, with time, change into an insolu= ble pigment. This can happen to to the stored powder, which= one day refuses to dissolve. The change occurs quite quickly= in solutions at about pH 5 that are used in conjunction with a magnesiu= m salt. The more acidic alcian blue solutions (pH 1 or 2.5) commonly= used for staining are usually stable for several months.
&nb sp;
Alcian blue 8G is available as a certified dye, so don'= t use non-certified stuff, which may not have been adequately= tested. Metanil yellow is not one of the dyes tested by the = Biological Stain Commission.
John KiernanAnatomy, UWO
London, Canada 
= = =<= BR>----- Original Message -----
From: Diana McCaig <dm=>
Date: Thursday, April 3, 200= 8 10:23
Subject: [Histonet] Alcian Blue-Metanil Yellow<= BR>To:

>= Is anyone using this stain.  We were doing this stain
= > routinely on all
> esophagus biopsies. = Originally it was done manually then
> programmed on> an autostainer.
>= The stain worked great but recently we have been experiencing problems< BR>> with uneven, inconsistent staining.  Has anyo= ne else had
> problems with
> this stain?=
> Diana
> ___________ _______________________ 5F= ____________
> Histonet mailing li= st
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