Description_x000D_ Specificity_x000D_ Peroxidase substrate suitable for use in immunoblotting and immunohistological staining procedures. This substrate produces an insoluble end product that is brown in color and can be observed visually._x000D_ Application_x000D_ 3,3′-Diaminobenzidine tetrahydrochloride has been used for immunohistochemistry._x000D_ Reagent for spectrophotometric determination of selenium._x000D_ Biochem/physiol Actions_x000D_ 3,3′-Diaminobenzidine tetrahydrochloride is a chromogenic substrate, which is commonly used in immunoperoxidase tests._x000D_ Reconstitution_x000D_ Dissolve 1 tablet in 15 ml of Tris-buffered saline, pH 7.6. Add 12 μl of fresh 30% hydrogen peroxide. DAB and hydrogen peroxide concentration may be adjusted to suit individual applications.