PhosphoWorks™ Colorimetric MESG Phosphate Assay Kit *UV absorption*

PhosphoWorks™ Colorimetric MESG Phosphate Assay Kit

UV absorption

PhosphoWorks™ Colorimetric MESG Phosphate Assay Kit *UV Absorption* is a colorimetric assay kit for quantifying inorganic phosphate (Pi) in solution and measuring phosphate release from Pi-generating enzymes.

Detection Principle: MESG conversion by PNP increases absorbance at 360 nm.
Sensitivity: Quantifies phosphate down to 2 µM.
Chemistry: Uses MESG and purine nucleoside phosphorylase (PNP).
Workflow: Incubates 30 minutes at room temperature.
Applications: Supports phosphatase, ATPase, and GTPase activity measurements.

Phosphate dose response was measured with PhosphoWorks™ Colorimetric MESG Phosphate Assay Kit on a 96-well UV plate using a SpectraMax Plus microplate reader (Molecular Devices).

Protocol

SDS

Catalog	Size	Price	Quantity
21659	200 Tests	Price

Overview

In the presence of inorganic phosphate MESG is converted to 2-amino-6-mercapto-7-methlpurine by purine nucleoside phosphorylase (EC 2.4.2.1) with absorption wavelength shift to red. This feature has been used to develop our convenient MESG phosphate assay kit. Our kit provides all the essential reagents including MESG, phosphorylase and reaction buffer. The MESG substrate gives an absorbance increase at 360 nm on phosphorylysis at pH 6.5-8.5, and at pH 7.6 the change in extinction coefficient is 11,000 M-1cm-1. The assay is shown to quantitate phosphate in solution at concentrations at least down to 2 µM. It can be used to measure the kinetics of phosphate release from phosphatases (such as GTPases and ATPases) by coupling the two enzymatic reactions.

Citations

View all 3 citations: Citation Explorer

Biochemical characterization and assay development for adenylosuccinate synthetase Rv0357c from Mycobacterium tuberculosis

Authors:

Singh, Vigyasa and Zhang, Ran and Chen, Ke and Li, Zhong and Li, Hongmin

Journal:

Biochimica et Biophysica Acta (BBA)-Proteins and Proteomics (2026): 141167

Sacrificial crystal templating of hyaluronic acid-based hydrogels

Authors:

Thomas, Richelle C and Chung, Paul E and Modi, Shan P and Hardy, John G and Schmidt, Christine E

Journal:

European Polymer Journal (2016)

Osteogenic cell cultures cannot utilize exogenous sources of synthetic polyphosphate for mineralization

Authors:

Ariganello, Marianne B and Omelon, Sidney and Variola, Fabio and Wazen, Rima M and Moffatt, Pierre and Nanci, Antonio

Journal:

Journal of cellular biochemistry (2014): 2089--2102

References

View all 8 references: Citation Explorer

Relationship between activating and editing functions of the adenylation domain of apo-tyrocidin synthetase 1 (apo-TY1)

Authors:

Bucevic-Popovic V, Pavela-Vrancic M, Dieckmann R, Von Dohren H.

Journal:

Biochimie (2006): 265

Purine nucleoside phosphorylase activity in rat cerebrospinal fluid

Authors:

Silva RG, Santos DS, Basso LA, Oses JP, Wofchuk S, Portela LV, Souza DO.

Journal:

Neurochem Res (2004): 1831

Characterization of the interactions between the small GTPase RhoA and its guanine nucleotide exchange factors

Authors:

Tan YC, Wu H, Wang WN, Zheng Y, Wang ZX.

Journal:

Anal Biochem (2002): 156

A continuous spectrophotometric assay for aspartate transcarbamylase and ATPases

Authors:

Rieger CE, Lee J, Turnbull JL.

Journal:

Anal Biochem (1997): 86

Continuous monitoring of Pi release following nucleotide hydrolysis in actin or tubulin assembly using 2-amino-6-mercapto-7-methylpurine ribonucleoside and purine-nucleoside phosphorylase as an enzyme-linked assay

Authors:

Melki R, Fievez S, Carlier MF.

Journal:

Biochemistry (1996): 12038

Usage and storage

Intended use

Research Use Only (RUO)

Instrument settings

Spectrophotometer
Absorbance	360 nm
Recommended plate	Clear UV-transparent

Absorbance microplate reader
Absorbance	360 nm
Recommended plate	Clear bottom

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Email	sales@aatbio.com
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Page updated on October 28, 2026

Component A: Assay Buffer	1 bottle (10 mL)
Component B: MESG Substrate	1 vial (lyophilized powder)
Component C: Purine Nucleoside Phosphorylase (PNP)	1 vial (lyophilized powder)
Component D: 1 mM KH2PO4 Standard	1 vial (1 mL)