[Histonet] Melanin Bleach & IHC

[Katri Tuomala]

Hi Lisa,

I would not recommend the melanin bleach step before immuno. I've done
parallels with and without bleach and in some cases you'll lose the immuno
reactivity altogether for S100 and HMB45 antibodies. Some cases did stain,
but much less and it is not predictable.  We use a red chromogen for the
cases that are known to have endogenous pigment, therefore not confusing the
positive staining with the pigment.

Katri

Katri Tuomala
Department of Pathology
St.Joseph's Health Care
Hamilton, Ontario, Canada
----- Original Message ----- 
From: "Lisa Black" <LBlack <@t> carilion.com>
To: <Histonet <@t> lists.utsouthwestern.edu>
Sent: Wednesday, April 07, 2004 5:02 PM
Subject: [Histonet] Melanin Bleach & IHC


> Hello All,
>  Whenever we bleach a slide prior to IHC staining, the end result is
> sub-optimal.    Our protocol is to use 0.5% potassium permanganate and
> then oxalic acid for the bleach then to proceed with the automated IHC
> stain using Ventana's DAB I-View Kit.   Most of the tissue comes off the
> slide and the remaining tissue has poor morphology.  Does anyone have
> good advice for me?
> Thanks in advance,
> Lisa Black
> Carilion Consolidated Lab
> Roanoke, VA
>
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