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3,3′-Diaminobenzidine with CAS 91-95-2

what is of  3,3′-Diaminobenzidine with CAS 91-95-2?

3,3′-Diaminobenzidine (DAB) is a precursor to polybenzimidazole. DAB is frequently used in the immunohistochemical staining of nucleic acids and proteins. It can also be used to detect fingerprints in blood because that it can be oxidized by hydrogen peroxide in the presence of hemoglobin to give a dark-brown color. It can be prepared by treating 3, 3’-dichlorobenzidine with ammonia in the presence of copper catalyst at high temperature and pressure.

1.Quick details of  3,3′-Diaminobenzidine with CAS 91-95-2

CAS No.:91-95-2
Other Names:3,3-Diamonobenzidine
EINECS No.:202-110-6
Place of Origin:Jiangsu, China
Classification:General Reagents
Model Number:SR0101
content:≥ 98.0%
Appearance:dark red or brown crystalline powder
Melting point:172 ~ 180 ℃

2.Description of 3,3′-Diaminobenzidine with CAS 91-95-2

Melting point 175-177 °C(lit.)
Boiling point 344.41°C (rough estimate)
density 1.1726 (rough estimate)
refractive index 1.5000 (estimate)
Fp 12 °C
storage temp. room temp
solubility 0.55g/l
pka 4.39±0.10(Predicted)
form tablet
color Crystals from MeOH
PH 7 (1g/l, H2O, 20℃)
Water Solubility 0.55 g/L (20 ºC)
Sensitive Light Sensitive
BRN 1212988
Stability: Stability Moisture and light sensitive. Incompatible with strong oxidizing agents.
CAS DataBase Reference 91-95-2(CAS DataBase Reference)
NIST Chemistry Reference 3,3′-Diaminobenzidine(91-95-2)
EPA Substance Registry System 3,3′-Diaminobenzidine (91-95-2)


3,3′-Diaminobenzidine is used for preparation of high-strength material such as nucleic acid stain and resistance high-temperature polymers such as bullet-proof vests.