Dear John,

Wouldn't the melanin also reduce the silver, since it argentaffilic?

> On Thu, 24 Feb 2000, Forney Constance M Civ 74 MDSS/SGSC wrote:
> 
> > Also - my pathologist wants his DAB to stain black instead of brown
> > - anyone have a procedure for that ?
> 
>   This is done by including cobalt or nickel ions in the 
>   DAB-containing incubation medium. Any textbook should 
>   have a recipe. The colour of the oxidation product is 
>   blue-black instead of brown. There are also silver
>   methods for amplifying the brown product, but these are
>   quite complicated procedures.
Tony Henwood
Senior Scientist
Anatomical Pathology
Royal Prince Alfred Hospital
Sydney, AUSTRALIA

http://www2.one.net.au/~henwood
http://www.pathsearch.com/homepages/TonyHenwood/default.html