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P4664

o-Phenylenediamine dihydrochloride

Name: <I>o</I>-Phenylenediamine dihydrochloride
Brand: SIGMA

chromogenic, tablet

Synonym(s):

1,2-Phenylenediamine tablet, OPD, OPD Tablet

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About This Item

Linear Formula:

C₆H₄(NH₂)₂·2HCl

CAS Number:

615-28-1

Molecular Weight:

181.06

NACRES:

NA.83

PubChem Substance ID:

24898491

UNSPSC Code:

12352204

MDL number:

MFCD00012966

Beilstein/REAXYS Number:

3912045

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Properties

Product Name

o-Phenylenediamine dihydrochloride, tablet, 15 mg substrate per tablet

Quality Level

200

form

tablet

mp

258 °C (dec.) (lit.)

solubility

water: 1 tablet/10 mL, clear, colorless

storage temp.

2-8°C

SMILES string

Cl[H].Cl[H].Nc1ccccc1N

InChI

1S/C6H8N2.2ClH/c7-5-3-1-2-4-6(5)8;;/h1-4H,7-8H2;2*1H

InChI key

RIIWUGSYXOBDMC-UHFFFAOYSA-N

Description

General description

o-Phenylenediamine dihydrochloride (OPD) is a chromogenic substrate that can be used in enzyme-linked immunosorbent assay (ELISA) procedures as it utilizes horseradish peroxidase conjugates. The substrate produces a soluble end product that is orange-brown and can be read spectrophotometrically at 450 nm. The OPD reaction may be stopped with 3N HCl or 3M H2SO4 and read at 492 nm.

Application

o-Phenylenediamine dihydrochloride has been used:

as a substrate in conventional capture enzyme-linked immunosorbent assay (ELISA) for recombinant hemagglutinin (rHA) protein detection
as a substrate for the determination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) antibodies by ELISA
as a colorimetric reagent specific for horseradish peroxidase (HRP) activity assessment in an ELISA protocol using SARS-CoV-2 antigens for S protein

Preparation Note

Dissolve one tablet in 0.05 M phosphate-citrate buffer, pH 5.0, to the desired concentration (typically an OPD concentration of 0.4 mg/ml is used). Add 40 μl of fresh 30% hydrogen peroxide per 100 ml of substrate buffer solution, immediately prior to use. Tablets are individually packaged in foil packets.