I can only tell you that until I started washing in 0.1% Triton in PBS 
was I able to eliminate background, but this is on 20 micron tissue 
sections. Of course, you have to peroxide quench before, and you have to 
block with normal serum from the same species as your your secondary Ab.
IE if you have goat anti mouse secondary, then normal goat serum.
Hope this helps.

-Kathleen
On Friday, December 5, 2003, at 11:32  AM, Scholz, Stephen J. wrote:

> Hello Histonet,
>
> I am having a problem with background staining on IHC slides.  This is 
> only happening in cell block specimens.  Is this common on cell 
> blocks?  Should I do a pretreatment on these?  What pretreatments do 
> others prefer?  Should I peroxide quench?  Before or after?  What about 
> blockers?  Do I ramble on and ask to many questions?
>
> Thanks for all your help,
>
> Stephen J. Scholz HT(ASCP)
> Histology Coordinator
> OSF St. Anthony Medical Center
> Rockford IL
>
> Phone: 815-395-5410
> Fax: 815-395-5364
> e-mail: sjscholz@osfhealthcare.org
>