Tetrahydrochloride 3,3 -diaminobenzidine

Diaminobenzidine tetrahydrochloride (2H2O) [7411-49-6] M 396.1, m >300°(dec), pK ,t(D) --3.3, pKEst(2) 4 7 (free base). Dissolved in water and ppted by adding cone HCl, then dried over solid NaOH. 

Fluorine-containing aromatic poly(benzimidazole)s are synthesized by direct polycondensation of 2,2-bis(4-carboxyphenyl)-l, 1,1,3,3,3-hexafluoropropane (15) with 3,3 -diaminobenzidine tetrahydrochloride (23) (Scheme 13) and 1,2,4,5-benzenetetramine tetrahydrochloride (24) (Scheme 14) in PMMA or PPA.24... 

Chromogen solution 3, 3 diaminobenzidine tetrahydrochloride (DAB) (Sigma St. Louis, MO) 30% hydrogen peroxide (H2O2) see Note 3). 

Develop the peroxidase in 3,3-diaminobenzidine tetrahydrochloride (DAB) solution 3 ml DAB stock solution and 12 drops hydrogen peroxide (30% w/v) are dissolved in 400 ml TBS incubate the specimen with this solution for 10 min (perhaps longer, control with microscope) Wash with tap water... 

DIAMINOBENZIDENE see BGK500 3,3 -DIAMINOBENZIDINE TETRAHYDROCHLORIDE see BGK750 6,6 -DIANnNO-m,m -BIPHENOL see DMI400 4,4 -DIAMINOBIPHENYL see BBXOOO p,p -DIAMINOBIPHENYL see BBXOOO 4,4 -DIAMINO-l,l -BIPHENYL see BBXOOO 4,4 -DIAMINOBIPHENYL-3,3 -DICARBOXYLIC ACID see BFX250... 

In the development of the specific antigens, the immunoperoxidase methods are used [147]. At 4°C, the overnight incubation of acetone-fixed frozen sections in the presence of the primary antibody is followed by developing immunoperoxidase with 3,3 -diaminobenzidine tetrahydrochloride. At 4°C, the overnight deparaffination of acetone-fixed frozen sections in the presence of the primary antibody is also followed by developing immunoperoxidase with 3,3 -diaminobenzidine... 

Peroxidase substrate 0.03% (w/v) 3,3 -diaminobenzidine tetrahydrochloride (DAB) in Tns buffer. Aliquots of this solution may be stored frozen and are stable for several months. Add H2O2 to a final concentration of 0.01% (v/v) just before use (see Note 11). 

Poly(benzimidazoles) are produced from dicarboxylic acids and aromatic tetramines. Commercially, 3,3 -diaminobenzidine tetrahydrochloride and diphenyl isophthalate are preferentially used. The diphenyl ester is used because (a) the free acids decarboxylate under the high reaction temperatures of 250-400 C (b) the acyl chlorides react too fast, making ring closure difficult and (c) the amino groups are partially methylated if the methyl esters are used. The hydrochloride is used because it is more stable to oxidation than the free amine itself. The polycondensation is carried out in two stages. A prepolymer. A, is formed in the first stage with foaming and phenol elimination ... 

DAB = 3,3 -diaminobenzidine tetrahydrochloride dihydrate. Cat. no. 5972SA from BRL. Caution Handle with extreme care in fume-hood using protection for eyes and hands. For a stock solution, add 10 mL of 0.05MTris-HCl buffer, pH 7.6, to 100 mg DAB powder. Mix well. Transfer in 1-mL aliquots to Eppendorf tubes. Wrap each Eppendorf tube in foil (DAB is light sensitive) and store at -20 C. A 0.05% solution should be made up just before use Mix 575 pL of 0.05M Tris-HCl, pH 7.6,0.OIM imidazole, plus 33.75 pL DAB stock solution and 18.75 pL hydrogen peroxide. 

Figure 7.10 Peroxidase-catalyzed reaction of 3,3 -diaminobenzidine tetrahydrochloride (DAB) with H2O2.

DAB (3,3 -diaminobenzidine tetrahydrochloride) solution, 1 mg/ml in 100 mM Tris-Cl (pH 7.6) prepared from a 10 mg/ml stock solution of DAB in H O, passed through a 0.2-pm, 25-mm Nalgene disposable syringe filter DAB is light-sensitive HjOj (30%)... 

Diaminobenzidine tetrahydrochloride (DAB) is a carcinogen. Handle with extreme care. Avoid breathing vapors. Wear appropriate gloves and safety glasses and use in a chemical fume hood. 

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