On Thu, 14 Dec 2000, Dawson, Glen wrote:

> Sorry John,
> I have to disagree on your assertion that a DAB solution should be clear or
> nearly clear.  Though the freshest of DAB solutions are fairly clear,
> moderately brown solutions do not mean they are unuseable.  I have received
> DAB which, though just shipped, turned quite brown.  This worried me a bit
> but I tried it anyway since it was all I had on hand.  It worked fine with
> no background. 

I suppose you're luckier than me. I got lots of background
from brown DAB in the 1970s and early 1980s. Since ?1985 I
haven't seen any that's been more than the slightly brown
either as solid or solution.
                               John Kiernan
 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1