>Sorry, this won't help you at all, but I use a similar technique and 
>I have never encountered this problem.


Do you filter your DAB/nickel solution before applying it to the tissue?

Cathy


At 3:35 PM -0400 25/4/02, Donna McCleary wrote:
>Hello histonet!
>
>I am currently using an ABC immunostain protocol that incorporates 
>DAB and nickel for visualization.  Unfortunately, I sometimes get
>intense staining of my no primary controls.  In the past, making up 
>a fresh batch of TBS solved the problem, however today the fresh TBS
>still turned my no primary controls (and all the other tissue as 
>well) into charcoal.  Has anyone else encountered this and what was 
>your
>solution?
>
>
>Donna McCleary
>Graduate Assistant
>Pharmacology & Therapeutics
>University of South Florida
>College of Medicine


-- 
---------------------------------------------------
Cathy Gorrie
Scientific Officer
Neural Injury Research Unit,
School of Medical Sciences,
University of New South Wales
Sydney, N.S.W. 2052

Phone: 61-2-9385 2462
Fax   : 61-2-9313 6252
e-mail: c.gorrie@unsw.edu.au