I normally add just a tiny bit of horseradish peroxidase (HRP) into the DAB
solution.  The color should turn brown instantly!  If you are using Vector
ABC kit, just use both A and B reagent without conjugating.  Hope this
helps.
Su

> -----Original Message-----
> From:	Tibor Ric [SMTP:tibor@home.se]
> Sent:	Tuesday, December 12, 2000 4:46 PM
> To:	HistoNet@pathology.swmed.edu
> Subject:	is there a simple way of testing DAB solution
>
> Hi Everygody!
>
> Here I come with (maybe a stupid) a question.
>
> Me and my friends at our lab wonder if there is a simple way of testing
> our
> DAB solution. I mean is it possible to check if the DAB solution still is
> working without setting up an application?
>
> Is there some chemical way of testing?
>
> Thanks in advance!
>
> Tibor Ric
> Biomedical Laboratory Techonologist/Scientist,
> Karlstad,
>  Sweden
>
>