Description_x000D_ Specificity_x000D_ o-Dianisidine (3,3′-dimethoxybenzidine) is a peroxidase substrate suitable for use in ELISA procedures. This substrate produces a soluble end product that is yellow-orange in color and can be read spectrophotometrically at 405 nm. The reaction may be stopped with 5 M HCl._x000D_ Packaging_x000D_ 50, 100 tablets in glass bottle_x000D_ Warning_x000D_ Probably carcinogenic._x000D_ Reconstitution_x000D_ Dissolve one tablet in 60 ml of 50 mM phosphate-citrate buffer, pH 5.0. Add 12 μl of fresh 30% hydrogen peroxide immediately before to use.