[Histonet] CD20 suddenly has high background

[Sandra Cheasty]

We do CD20 on canine and feline samples and are suddenly getting lots of non-specific background. We use:

 

CD3, F7.2.38 from DAKO diluted 1:400

LSAB+ and DAB+

Avidin and Biotin block

 

I even tried it with a polymer detection kit, but to no avail. Has anyone else had recent difficulty with this T cell marker?

 

Thanks,

Sandy