PNPP, Disodium Salt is a colorimetric alkaline phosphatase soluble substrate, p-Nitrophenyl Phosphate (pNPP) is the substrate of choice for use with alkaline phosphatase in Enzyme Linked Immunosorbant Assay (ELISA) procedures.
Excellent substrate for alkaline phosphatase-based ELISA assays. Produces a yellow soluble end product that can be read at 405 nm to 410 nm. Both kinetic and endpoint determinations can be performed. ε max: ≥9600 cm-1 M-1 at 311 nm in 0.4 M Na2CO3.
Primary TargetSubstrate for phosphatase
Dissolve it in hot aqueous MeOH, filter and precipitate it by adding Me2CO. Wash the solid with Me2CO and repeat the purification. Aqueous MeOH and Et2O can also be used as solvents. The white fibrous crystals contain less than 1% of free 4-nitrophenol [assay: Axelrod J Biol Chem 167 57 1947]. [Beilstein 6 IV 1327.]
