0,0 -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. 

Selenium Selenium converted to 3,3-diaminobenzidine piezselenol, which is extracted into toluene and back-extracted into 0.5 M hydrochloric acid Complex deposited on a mercury electrode at -0.45 V 0.01 ng Se absolute [542]... 

Diaminobenzidine horseradish peroxidase, and ABTS or o-diansidine titanium reagent Fomey et al. (27) Highley and Murmanis (28) Illman and Highley (30) Micales and Highley (31)... 

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... 

Enzymes. Enzymes too are useful labels and several have been employed, with peroxidase and alkaline phosphatase being the most popular to date. One important feature of this technique is for the enzyme to be able to convert a soluble substrate into an insoluble product in order to localize the antigen properly. Several suitable substrates are available with 3 3 -diaminobenzidine (DAB) and 3-amino-9-ethylcarbazole (AEC) being used with peroxidase and 5-bromo-4-chloro-3-indoylphosphate/nitroblue tetrazolium (BCIP/NBT) with alkaline phosphatase. 

The synthesis of tpbq was adopted from the procedure published by Rillema et al. [26], 3,3 -diaminobenzidine (0.5 g, 2.34 mmol) and 2,2 -pyridyl (1.0 g, 4.67 mmol) were placed in a round bottom flask. Then 50 mL of absolute ethanol was added into the flask, stirred, and heated under reflux for 5 hours, where a brownish-yellow precipitate formed. The product was filtered, washed with small portions of cold ethanol, followed by ether, then vacuum-dried, and stored in a desiccator. A typical yield is -45% m/z 567.8 UV-Vis (nm) 367.5, 281 FTIR (cm ) 3,060.5, 3,010.4, 1,999.2, 1,613.2-1,570.8, 1,474, 1,281-999.61, 891.54-710.15, 663. 

Colorimetric methods were developed as a nonradioactive alternate method of detection. Enzymes such as HRP or AP, which are usually conjugated to the secondary antibody, can convert substrates to colored precipitates that accumulate on the blot and generate a colored signal. Such substrates include 5-bromo-4-chloro-3-indolyl phosphate/nitroblue tetrazolium (BCIP/NBT) for AP and 3,3 -diaminobenzidine... 

In addition to the many enzyme systems available, there are with each a series of chromogenic substrate solutions that can be used to create different colors and locations of reaction products. For the peroxidase system, there are numerous oxidizable compounds that precipitate as a permanent color. The most common and still widely used is 3,3 diaminobenzidine tetrahydro-chloride (DAB). This compound precipitates to a golden brown color when in solution with peroxidase and hydrogen peroxide. This brown color has many subtleties and readily stands out in a tissue section. With practice, it is possible to differentiate specific from nonspecific staining patterns just by examining the characteristics of the precipitated pigment. This material is also insoluble in alcohol and xylene, and therefore the tissue may be routinely dehydrated and cleared without loss of chromogen. 

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

Wear disposable gloves while handling slides covered with chromogen. Particularly, 3,3-diaminobenzidine (DAB) is a chromogen that is a well-known carcinogen. 

Polyimides are obtained from amine and carboxyl reactants when the ratio of amine to acid functional groups is 1 2. If reactants with the reverse ratio of amine to acid functional groups are employed, polybenzimidazoles (PBI) are produced for instance, polymerization of 3,3 diaminobenzidine and diphenyl isophthalate yields poly[(5,5 -bi-liT-benzimidazole]-2,2 -diyl)-l,3-phenylene] (Lilia) (Eq. 2-216) [Buckley et al., 1988 Hergenrother, 1987 ... 

An aliquot of 3,3 -diaminobenzidine (119 mmol) was placed in a three-neck flask and then dissolved in N, /V-dimcthylacetamide (200 g) and purged with nitrogen. This mixture was then treated with adamantanetetracarbonyl chloride (7.8 mmol) as a... 

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... 

Peroxidase substrate (DAB). 2 5 mg of 3,3-diaminobenzidine tetrahydrochlonde dissolved m 5 mL phosphate-buffered saline (PBS). Add 2 pL of 30% hydrogen peroxide (H2O2). DAB powder should be handled only in a fume cupboard. 

Cytochemical identification of peroxidase was conducted in infected wound margins in the cell walls and degenerating cytoplasm of wheat leaves with 3,3 -diaminobenzidine (Thorpe and Hall, 1984). The same substrate... 

Yamaguchi, I., Osakada, K., Yamamoto, T., Polyrotaxane containing a blocking group in every structural unit of the polymer chain. Direct synthesis of poly(alkylenebenzimidazole) rotaxane from Ru complex-catalyzed reaction of 1,12-dodecanediol and 3,3-diaminobenzidine in the presence of cyclodextrin. J. Am. Chem. Soc. 1996, 118, 1811-1812. 

Novikoff AB, Novikoff PM, Quintana N, Davis C. Diffusion artifacts in 3,3 -diaminobenzidine cytochemistry. J Histochem Cytochem 1972 20 745-749. 

Polypyrazoles of the type 62 have been prepared.65 These polymers are formed from the low-temperature solution condensation of 1,1 -bis(diketo)ferrocenes with aromatic or pseudoaromatic dihydrazines to give polyhydrazones which are transformed thermally to the polypyrazoles. Polybenzimadazole (63) has been prepared68 from l,l -ferrocenedicarboxylic acid and 3,3 -diaminobenzidine. 

Reucroft et al. 37>38 reported photoconductivity of polymers with polyconjugation in the chain, prepared by polycondensation of 3,3 -diaminobenzidine and 3,3, 4,4 -benzophenone tetracarboxylic acid dianhydride39, pyrrone polymers ... 

Figure 3.118 Synthesis of bis-carbene ligands on a 3,3 -diaminobenzidine scaffold.

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