DAB Dilution Buffer 10x Concentrate, for use with ES005; 50 mL

Since first introduced by Graham and Karnovsky (1966), numerous procedures for its use in histochemistry, immunohistochemistry, Western and dot blots have been described (Lewis & Knight, 1977; Larsson, 1988; Gallyas et al., 1982). In the presence of horseradish peroxidase and hydrogen peroxide, DAB oxidatively polymerizes to an insoluble brown polymer. The color can be modified and intensified by treatment with metal salts of silver, copper, nickel, cobalt and osmium (Hsu & Soban, 1982). DAB is a suspected carcinogen and must be handled with caution. CHEMICON supplies DAB as a stable liquid concentrate eliminating the necessity of handling a potentially hazardous material. The stabilization system is unique and prevents formation of partially oxidized DAB excluding nonspecific binding to other heme containing proteins so often observed with powdered DAB preparations. The concentrate can be diluted in appropriate peroxide containing buffers providing the researcher with the capability of formulating any of the numerous published DAB reaction systems. The most common procedure suggests diluting the DAB (Catalog Number ES005) 1:50 in a 100 μmol/L Tris-HCl buffer, pH 7.6, and adding H(2)O(2), to a final concentration of 0.01%. Incubation times range from 5-15 minutes. Prolonged reaction time will result in non-specific staining of other heme proteins.