|The pNPP (p-NitroPhenyl Phosphate) liquid, ready-to-use substrate is a highly active and stable formulation utilized for measuring AP- (Alkaline Phosphatase) probe activity.
The solution is a solvent free buffer solution containing stabilized pNPP.
In kinetic assays p-nitrophenol appears yellow and is measured at 405 /650 nm.
If stopped reactions are preferred, add equal amounts of 1 .0 M sodium hydroxide solution and read the absorbance at 405 /650 nm. The stability life time is 2 years from date of manufacturing.