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help: the principle of DAB reaction - immunohistochemistry (Aug/02/2005 )

what's the principle of DAB/HRP reaction?
I just know a little, but it seems not enough……
does anyone know more about it?


In the presence of H202 (hydrogen peroxide) DAB is converted to an insoluble brown reaction product and water by the enzyme HRP (horse radish peroxidase) so the reaction is something like this:

DAB + H202 ----------HRP----------> DAB ppt + H20

So if you have a HRP attached to your antibody which is bound to your antigen in a particular area of a section and you add DAB and H202 the reaction will proceed like any other enzymatic reaction and produce an insoluble brown DAB ppt and H20 in the area of your section where the antibody has bound antigen.


thank u very much! smile.gif
That's just what I can find.
But still, sad.gif I was scolded by the professor this afternoon, because she wants more about it……

now, can anyone tell me the chemical character of DAB


DAB, or 3,3'-diaminobenzidine for close people, is a commonly used chromogen for immunohistochemical staining. In the presence of a peroxidase enzyme, DAB will produce a brown precipitate that is insoluble in alcohol. The slides may be dehydrated through alcohols to xylene and mounted with any commercially available mounting media.

first elements are well at :here

but if you can read french, you'll get all infos here


Fred33, thank u for the websites
unfortunately, writing english is difficult to me, unsure.gif not to mention french……

tongue.gif But I have found more details in the internet: just here