[Histonet] Background in frozen pancreas sections

[Martin S.]

Hi All,
 
I've been doing some CD8 staining of frozen sections of mouse pancreas
with autoimmune insulitis. The CD8 staining is good (using rat antiCD8 +
goat anti rat:Biotin + ABC/HRP + DAB) but there is high background
staining. The problem is I get a lot of brown/grey background in the
exocrine cells but the islets are completely clean.
I've tried numerous different blocks containing BSA, goat serum and/or
mouse serum and/or Tween I've also tried using avidin/biotin block
(Vector), this actually increased the background.
 
Any suggestions?
 
 
Thanks
Sonya