Dako's liquid DAB is good but it's not a magic formula.  The following
should be at least as sensitive but won't keep for as long (I prepare it
fresh each day).

0.005M Tris-HCL 100mLs
DAB 10mg
Imidazole 6mg
Tween 20  0.1mL
6% H2O2 0.4mLs

If there are any budding chemists out there who can help with the shelf-life
I'd be interested too. I'm currently experimenting with preservatives such
as sodium sulphite and metabisulphite.

Good luck


-- 
Lawrence Brett
Immunocytochemistry Lab.
Pathology Dept.
Western General Hospital
Crewe Road South
Edinburgh  EH4 2XU
Scotland. UK
Tel: 0131 537 2148
email: lauriebrett@bigfoot.com