Hi,

I at first thought you were experiencing the same problem I have had in the
past. I have experienced a Pokka dot like pattern when staining immunos but
it was on the slide as well as the tissue. The markings seem to be stained
with AEC and in a very organized pattern and round. I have attributed it to
a problem with the company coating the slides and not properly doing QC. It
became so frequent I changed companies and have not had a problem since. 
When I looked at the pictures it seemed to be just on the tissue, is that
the case? If it is on the slide to, where are you getting your slides from? 

Good Luck,

Jennifer Harvey
University of Rochester
> ----------
> From: 	bliven.laura@marshfieldclinic.org
> Sent: 	Wednesday, October 30, 2002 2:26 PM
> To: 	histonet@pathology.swmed.edu
> Subject: 	Artefact on IHC slides
> 
> 
> Please view pictures on:
> histonet.org and click on View List Serv Images
> to view ipproblem1.jpg and ipproblem2.jpg.
> 
> The stain is IHC CD20 on a biopsy specimen using DAB as the chromogen and
> Hematoxylin as the counterstain.
> 
> As far as I know, the tissue didn't come in contact with gauze and the
> artifact pattern isn't consistent with our tissue cassettes.  Just curious
> as to any/all answers on this one.
> 
> Thanks,
> Laura Bliven
> Marshfield Laboratories
> bliven.laura@marshfieldclinic.org
> 
> 
>