CAS No. 868272-85-9

Batch: Purity:99.51
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3,3'-Diaminobenzidine tetrahydrochloride Chemical Structure
Chemical Structure
Check the 3,3'-Diaminobenzidine tetrahydrochloride product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Chemical Information

CAS Number 868272-85-9
Molecular Formula

C12H14N4.4ClH.H2O
Molecular Weight (MW) 378.1254
SMILES O.Cl.Cl.Cl.Cl.NC1=C(N)C=C(C=C1)C2=CC(=C(N)C=C2)N

Biological Activity

3,3'-Diaminobenzidine tetrahydrochloride (DAB) is a chromogenic substrate for horseradish peroxidase (HRP) used to visualize cellular and tissue target molecules. Upon enzymatic oxidation by HRP in the presence of hydrogen peroxide, DAB yields an insoluble, dark-brown polymer precipitate at the site of enzymatic activity. This oxidation reaction enables precise localization and detection of antibody-bound antigens or nucleic acids in immunohistochemistry and in situ hybridization assays.[1][2]

How to Prepare Stock Solution?

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Solubility

Batch:
All in vitro solubility values are batch-tested experimental data (non-literature values).
Solvent Solubility & Note
DMSO 54 mg/mL (142.8 mM)
(Moisture-contaminated DMSO may reduce solubility. Use fresh, anhydrous DMSO. The recommended stock concentration is 10 mM in DMSO.)
Water 54 mg/mL
Ethanol Insoluble
FAQ
Q: Why does a DMSO stock precipitate in media/saline?
A: It is caused by unheated aqueous media (supersaturation), local solvent shock, or incorrect mixing sequence.
How to fix it?
  • Preheat media/saline to 37°C.
  • Mix rapidly (pipette/vortex) upon addition.
  • For complex mixes, always add the aqueous phase last.
  • Re-dissolve minor precipitates with a 37°C water bath and sonication (≤30 min).

Reference

[1] Graham RC Jr, Karnovsky MJ. J Histochem Cytochem. 1966;14(4):291-302.

[2] Nakane PK, Pierce GB Jr. J Histochem Cytochem. 1966;14(12):929-931.

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Note: Technical data last updated: Sep 1, 2026.