| Bioactivity | PNPP (Para-nitrophenyl phosphate) disodium is a non-proteinaceous chromogenic substrate for alkaline and acid phosphatases used in ELISA and conventional spectrophotometric assays. |
| Invitro | Phosphatases catalyze the hydrolysis of PNPP liberating inorganic phosphate and the conjugate base of para-nitrophenol (pNP). The resulting phenolate is yellow, with a maximal absorption at 405 nm[1]. |
| Name | PNPP disodium |
| CAS | 4264-83-9 |
| Formula | C6H4NNa2O6P |
| Molar Mass | 263.05 |
| Appearance | Solid |
| Transport | Room temperature in continental US; may vary elsewhere. |
| Storage | 4°C, sealed storage, away from moisture *In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture) |
| Reference | [1]. Crowther JR, et al. Evaluation of the use of chromogenic and fluorogenic substrates in solid-phase enzyme linked immunosorbent assays (ELISA). Biologicals. 1990 Oct;18(4):331-6. |