Another thing to think about is that with any really bloody specimens 
(such as the spleen) you may not be doing an adequate peroxide block.  
Either increase the time, or do a double application...  just a thought.
Bonnie Whitaker 
UT Houston Medical School

----- Original Message -----
From: Patti Loykasek <ploykasek@phenopath.com>
Date: Thursday, July 5, 2001 11:30 am
Subject: Re: background on CD20 & CD21 stained slides

> If you are using Envision+ for detection, the background can't be from
> biotin. Have you tried titering out your antibodies? I have found 
> Envisionto be a very clean detection system, and usually no need 
> for even a serum
> block. Take one of your antibodies, and do some doubling titers 
> with it.
> What are you using for a diluent? Also, what did you use in place 
> of the
> primary when you used the spleen without either antibody? How are you
> rinsing in between steps of your procedure? Both of those 
> antibodies can
> usually be used with very little background problems. If I think 
> of anything
> else, I'll send another post.
> 
> Patti Loykasek
> Phenopath Laboratories
> Seattle, WA 
> 
> 
>