o-Phenylenediamine dihydrochloride
SIGMA/P6787 - tablet, 2 mg substrate per tablet
Synonym: 1,2-Phenylenediamine tablet; OPD; OPD Tablet
CAS Number: 615-28-1
Empirical Formula (Hill Notation): C6H8N2 · 2HCl
Molecular Weight: 181.06
MDL Number: MFCD00012966
Linear Formula: C6H4(NH2)2·2HCl
Product Type: Chemical
| form | tablet |
| InChI | 1S/C6H8N2.2ClH/c7-5-3-1-2 |
| InChI key | RIIWUGSYXOBDMC-UHFFFAOYSA |
| mp | 258 °C (dec.) (lit.) |
| Quality Level | 200 ![]() |
| SMILES string | Cl[H].Cl[H].Nc1ccccc1N |
| storage temp. | 2-8°C |
| 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. |
| 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. |
| Symbol | ![]() ![]() GHS07,GHS08,GHS09 |
| Signal word | Warning |
| Hazard statements | H317 - H341 - H351 - H411 |
| Precautionary statements | P202 - P261 - P273 - P280 - P302 + P352 - P308 + P313 |
| Hazard Codes | Xn,N |
| Risk Statements | 22-40-43-50/53-68 |
| Safety Statements | 36/37-61 |
| RIDADR | UN 3077 9 / PGIII |
| WGK Germany | WGK 3 |
| mp | 258 °C (dec.) (lit.) |
| Storage Temp. | 2-8°C |
| UNSPSC | 12352204 |




