Hi,
    I am not sure what the details of the procedure you are using now are
but if it helps, this is what we do. We begin with the sections in distilled
water then antigen retrieve using DAKO epitope retrieval solution in a
steamer for 20 min. Then after the slides have cooled. We incubate at room
temperature and a titration of 1:500 in the primary antibody, CD31 also from
DAKO for 30 min. This is followed by Envision + (mouse) for 30 min. Formerly
we used LSAB + with acceptable results too. I have not heard of any
complaints, and the tissue appears to be staining the endothelial cells
properly with little or no background.
I hope this helps
Amos Brooks

Karen M Majahad wrote:

> Hello Histonetteers,
> I am having problems with the immunostaining of CD31 on mouse
> endothelial cells in paraffin sections. The antibody does not appear to
> be staining all of the enothelial cells. I have tried using trypsin and
> Vector Antigen unmasking solution. I have used several methods including
> using both trypsin and antigen unmasking solution for pretreatment
> methods. These sections are not tumors and have very new blood vessels
> forming. Any information would be helpful.
>
>                                                 Thanks
>                                                 K.Majahad@TKTX.com