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SIGMAFAST p-Nitrophenyl phosphate Tablets

tablet, To prepare 5 mL

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pNPP tablets
MDL number:

Quality Level




deionized water: soluble 5 mL

storage temp.


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deionized water: soluble 5 mL


water: 0.25 tablet/mL, clear, colorless


water: 1 tablet/mL, clear to hazy, colorless to faintly yellow



storage temp.


storage temp.


storage temp.


storage temp.



SIGMA FAST p-Nitrophenyl phosphate Tablets has been used:
  • to quantify non-secreted alkaline phosphatase to monitor differentiation of osteoblast-like cells (SaoS-2)
  • to stain murine preosteoblast MC3T3-E1 cells in alkaline phosphatase assay
  • as a substrate for ExtrAvidin® alkaline phosphatase to measure hemoglobin-bound α-synuclein using enzyme-linked immunosorbent assay (ELISA)
  • as a substrate for alkaline phosphatase conjugated antibodies for detection in ELISA of abirin toxin
Developed for use as a soluble substrate for the detection of alkaline phosphatase activity in Enzyme Immunoassays (EIA). pNPP is the substrate of choice in high sensitivity alkaline phosphatase-based EIA assays.One pNPP tablet and one Tris buffer tablet are dissolved in deionized water and provide a ready-to-use substrate. Each Sigma FAST pNPP tablet set yields a solution containing 1.0 mg/ml pNPP, 0.2 M Tris buffer. EIA applications using pNPP may be read in timed assays or stopped with 3N NaOH for delayed readings. SIGMAFAST require only the addition of distilled or deionized water to prepare an active substrate solution. Tablets are individually packaged in foil packets.


Each tablet set dissolved in 5 mL deionized water yields a ready-to-use buffered solution containing pNPP.

Legal Information

ExtrAvidin is a registered trademark of Merck KGaA, Darmstadt, Germany
SIGMAFAST is a trademark of Sigma-Aldrich Co. LLC

Storage Class Code

11 - Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

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Ruklanthi de Alwis et al.
The Journal of infectious diseases, 219(2), 295-304 (2018-10-16)
Nontyphoidal Salmonella (NTS) organisms are a major cause of gastroenteritis and bacteremia, but little is known about maternally acquired immunity and natural exposure in infant populations residing in areas where NTS disease is highly endemic. We recruited 503 pregnant mothers
Conall H Watson et al.
PLoS neglected tropical diseases, 11(7), e0005786-e0005786 (2017-07-21)
Fiji, an upper-middle income state in the Pacific Ocean, has experienced an increase in confirmed case notifications of enteric fever caused by Salmonella enterica serovar Typhi (S. Typhi). To characterize the epidemiology of typhoid exposure, we conducted a cross-sectional sero-epidemiological
Zimu Wu et al.
International journal of clinical and experimental pathology, 12(5), 1757-1763 (2020-01-15)
Post-stroke induction of alpha-synuclein (AS), a neuronal protein implicated in the pathogenesis of Parkinson's disease (PD), has been demonstrated to induce secondary brain damage after cerebral ischemia. Therefore, understanding the expression and pathogenic modifications of AS is clinically meaningful for
Ronit Rosenfeld et al.
Nature communications, 12(1), 944-944 (2021-02-13)
The coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibits high levels of mortality and morbidity and has dramatic consequences on human life, sociality and global economy. Neutralizing antibodies constitute a highly promising
Yuankun Zhai et al.
Journal of cellular physiology, 234(10), 18602-18614 (2019-03-27)
Homocysteine (Hcy) is detrimental to bone health in a mouse model of diet-induced hyperhomocysteinemia (HHcy). However, little is known about Hcy-mediated osteoblast dysfunction via mitochondrial oxidative damage. Hydrogen sulfide (H2 S) has potent antioxidant, anti-inflammatory, and antiapoptotic effects. In this


Nitroblue Tetrazolium (NBT) is used with the alkaline phosphatase substrate 5-Bromo- 4-Chloro-3-Indolyl Phosphate (BCIP) in western blotting and immunohistological staining procedures. These substrate systems produce an insoluble NBT diformazan end product that is blue to purple in color and can be observed visually.


ELISA protocols providing detailed instructions on performing indirect ELISA and Capture ELISA . Learn more about recommended products and techniques for performing both sandwich ELISA and indirect ELISA experiments.

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