pNPP (C09-1021-132)

Product Characteristics pNPP (p-nitrophenylphosphate) is a chromogenic substrate for Alkaline Phosphatase (AP). In the presence of AP, pNPP is hydrolyzed rapidly to pnitrophenol and inorganic phosphate. Liberated pnitrophenol is seen as a clear yellow color that is measured at 405/620 nm.pNPP, liquid ready-to-use substrate, is highly active compared to pNPP ONE (cat. No. P494181). The substrate gives superior results due to its sensitivity, allowing very low detection limits.Composition & Properties pNPP is a liquid, ready-to-use and aqueous formulation. The buffer solution contains stabilized pNPP and appropriate stabilizing components. Recommended stop solution is an equal volume of 0.1 M sodium hydroxide solution.Working Procedure 1.The desired amount of substrate is poured into a sealed container and allowed to reach room temperature in the dark. 2.Recommended volumes are 100 µl substrate solution per microtiter well. Development time is typically 15- 30 minutes. Optimal time is determined by the user and will vary according to the procedure and the incubation temperature. 3.100 µl of 0.1 M NaOH is then added and mixed thoroughly. 4.In kinetic assays, the color is read directly at 405 nm. For endpoint assays the absorbance is read at 405/620 nm.Tips & Tricks • For use in hot climate countries, due to superior background characteristics, we recommend pNPP ONE (cat. no. P494181) • A stop solution of 0.1 M NaOH requires no hazardous labelling. In case a higher assay sensitivity is required, a 1.0 M NaOH may be used as stop solution offering an approx. increase of OD of 3%. In both cases a 1 hour stop stability is guaranteed.Handling & Storage• Store solution at 2-8 °C in the dark. • Avoid exposure to light and heat. • Re-dispense only into bottles made of High Density Polyethylene (HDPE), amber color. Dispensing guidelines are available upon request. Specifications and Purity: Ready-to-use (RTU). Related Document: https://ald-pub-files.oss-cn-shanghai.aliyuncs.com/aladdinsci/pdp/sds/1/P494193-SCI_accb026bc53848cc3eadad28c70f0425.pdf.