Hi Rebekah,
It could be you are dealing with something else than endogenous peroxidase.
We need to know more detail of your method to try and think it through:
1.What animal is your primary antibody raised in and is it known to work on
sheep?
2.What are you using to block non-specific staining?
3.What animal is your secondary antibody raised in?
4. Are you working with formalin fixed, paraffin embedded or frozen
sections?
There are a lot of techs working on animal tissues on HistoNet. If you
provide more information, I'm sure help will be forthcoming...

Katri

Katri Tuomala
Department of Pathology
St.Joseph's Health Care
Hamilton,Ontario,Canada
----- Original Message ----- 
From: "SMITH,REBEKAH FELICIA" 
To: 
Sent: Wednesday, June 09, 2004 10:18 AM
Subject: [Histonet] blocking endogenous peroxidase when using ABC
stainingand DAB


> Hi,I'm working as a lab technician at UF making using
> immunohistochemistry (ABC method and then DAB, specifically) to
> find out where eNOS is located in sheep placenta tissue. However,
> I seem to be both not getting staining on the endothelial cells
> (which is weird since I'm using eNOS antibody) and getting a lot
> of staining due to endogenous peroxidase activity. I've already
> tried putting the slides in a solution of 1:10 30%hydrogen
> peroxide to methanol for as long 40 min, and it still doesn't seem
> to quench the endogenous peroxidase. Anyone have any suggestions
> as to other methods of quenching it?
> --
> SMITH,REBEKAH FELICIA
> "You are a child of the universe, no less than the trees and the
> stars
> You have a right to be here and whether or not it is clear to you,
> no doubt the universe is unfolding as it should. Therefore be at
> peace with G-d, whatever you conceive Him to be. And whatever your
> labors and aspirations,in the noisy confusion of life, keep peace
> in your soul.-Max Ehrmann,"Desiderata"
>
>
> _______________________________________________
> Histonet mailing list
> Histonet@lists.utsouthwestern.edu
> http://lists.utsouthwestern.edu/mailman/listinfo/histonet



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