Protein Phosphatase Activity Assays
Continuous Phosphatase Activity Assays For Real-Time Progress Curves In Every Well
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Flexible Configurations Built Around Our Substrates For Your Applications
PhosphoSens Substrates
Starting at $2,695
AssayQuant’s patented PhosphoSens® Technology is packed into thoughtfully designed peptide substrates for optimal target specificity. Each PhosphoSens Senor Peptide Substrate can be purchased as lyophilized 1mg aliquots. Each mg is sufficient for 2,000 reactions.
Evaluation Kits
Starting at $295
Designed for streamlined technology assessment, each discovery kit includes sufficient volumes of substrate and reaction reagents to perform 200 reactions.
Includes:
- PhosphoSens Substrate
- ATP, EGTA, DTT, Reaction Buffer and Dilution Buffer
Substrate Systems
Starting at $3,095
Designed for higher throughput applications AND ease of use, each Substrate System includes sufficient volumes of substrate, enzyme and reaction reagents to perform 2,000 reactions.
Includes:
- 1mg PhosphoSens Substrate
- ATP, EGTA, DTT, Reaction Buffer and Dilution Buffer
Kinase Activity Systems
Starting at $3,495
Ready-to-use systems include everything needed for fast, sensitive, and streamlined assay setup. Includes sufficient volumes of substrate, enzyme and reaction reagents to perform 2,000 reactions.
Includes:
- 1mg PhosphoSens Substrate
- 10ug Recombinant Kinase
- ATP, EGTA, DTT, Reaction Buffer and Dilution Buffer
We Have Validated Assays For 35+ Protein Phosphatases
A Direct, Continuous Fluorescence System for Measuring Phosphatase Activity and Inhibition
AssayQuant's PhosphoSens detection technology delivers a new standard for measure phosphatase activity by directly monitoring dephosphorylation of a sensor peptide substrate throughout the entire reaction. These assays capture real-time data at the substrate level, offering richer insights into enzyme kinetics, inhibitor interactions, and reaction dynamics—without the limitations of traditional endpoint assays.
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Not sure which product or service is the best fit for your project? At AssayQuant, our team of scientific experts can provide the guidance and support you need to achieve your research goals.
Assay Principle & Workflow
PhosphoSens assays leverages AssayQuant’s Proprietary Detection Technology to provide real-time, continuous measurements of phosphatase activity by directly detecting substrate dephosphorylation throughout the phosphatase reaction.
Sensor Peptide Substrates are developed with the Sox readout molecule, covalently attached via a cysteine residue in close proximity to the phosphorylation site (± 2-5 residues).
As the phosphatase acts on the phosphorylated substrate, dephosphorylation induces a chelation‑enhanced fluorescence (ChEF) signal proportional to phosphorylation level.

Add
Active enzyme is added to reaction mix containing a Sensor Peptide Substrate, catalyzing phosphotransfer from ATP to the substrate in real time.
Read
Add plate to reader and monitor kinase activity throughout the reaction. Signal is directly proportional to the phosphorylation level of the substrate.
Interested in Phosphatase Profiling?
Revolutionizing Phosphatase Research and Drug Development with Continuous Activity Assays
Continuous, Real-Time Monitoring
Captures the entire kinetic profile from start to finish. This approach yields the actual reaction rate, with high accuracy, precision, and confidence.
Direct Measurement of Enzyme Activity
Measures enzyme activity at the substrate level, avoiding the complications of indirect assays that require additional steps.
Physiologically Relevant Conditions
Use biologically relevant peptide substrate sequences in assays that are compatible with low to physiological [mM] concentrations of ATP.
Add & Read Workflow
Achieve fast and reproducible results with a homogenous, single-step workflow without compromising data quality.
Assays For Your Target
Browse Our Catalog Of 35+ Protein Phosphatase Activity Assays To Find The Right PhosphoSens Products For Your Experiments
PhosphoSens Phosphatase Assays Catalog
For your convenience, you can also download a PDF version to review later or share with your colleagues.
DownloadUnderstand How Our Technology Can Support Your Next Discovery
Deep Kinetic Characterization: When IC50 Isn't Enough
A continuous assay, like our PhosphoSens assay, that measures the catalytic event of phosphorylation in real time enables determination of kinetic parameters that power your drug discovery research.
Continuous vs. Endpoint Kinase Assays: What You Need to Know
PhosphoSens-Kinetic Phosphatase Inhibitor IC50 Determination
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