Phosphatase Profiling Services That Show You More Than % Inhibition
KinSight™ profiles your compounds against 48 validated phosphatases using continuous, real-time assays — delivering true selectivity data, TDI detection, and MOA insights that endpoint platforms systematically miss.
48
Protein phosphatases available
n=2
All assays run in duplicate
Customizable
Design your own panel
2 wks
Detailed report turnaround
Selectivity Is an Emerging Challenge in Phosphatase Drug Discovery
Phosphatases were long considered difficult, even undruggable, targets — their shallow, highly polar active sites resisted the kind of small-molecule design that worked for kinases. Renewed structural and chemical biology advances have changed that, and tyrosine and serine/threonine phosphatase inhibitors are now advancing across multiple therapeutic programs.
But as those programs mature, the same selectivity question kinase discovery already faced is showing up here too: catalytic domains within phosphatase families share enough structural similarity that a compound optimized against one target can retain meaningful activity against close relatives, and unrecognized off-target inhibition carries the same late-stage risk seen elsewhere in enzyme drug discovery.
Profiling that measures actual catalytic turnover — not an indirect proxy like DiFMUP hydrolysis — gives medicinal chemistry a real number to optimize against, and gives safety teams visibility into liabilities while they're still cheap to fix.
How KinSight Phosphatome Profiling Works
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1
Panel selection
Test against a single phosphatase, a focused subfamily, or the full 48 phosphatome panel — single-concentration screening or full dose-response, your choice..
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Continuous kinetic measurement, not a single frame
An endpoint read captures one moment after the reaction has already stopped — like judging a movie from a single frame. PhosphoSens® instead monitors every well throughout the entire reaction, so what you get is the full sequence, not a still.
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Kinetics that separate compounds an endpoint can't
Two compounds can show nearly identical inhibition at a single timepoint and still be doing very different things underneath — one fast and reversible, one slow and time-dependent, one covalent. KinSight's progress-curve analysis resolves that difference directly, flagging TDI, slow-binding behavior, and mechanism-of-action signals that a single % inhibition value collapses into one indistinguishable number.
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Reporting built for a decision, not just a data pull.
Waterfall plots, an interactive phosphatome tree overlay, tabular exports, and annotated progress curves for every well — reviewed by our scientists before you receive it — delivered within two weeks.
What's in your data package?
- ✓Waterfall plots ranked by % inhibition across all targets
- ✓Annotated phosphatome tree visualization
- ✓Tabular % inhibition data export
- ✓Progress curves for every well (not just endpoint)
- ✓TDI, slow-binding, and unusual kinetics flagged by scientists
- ✓MOA insights and selectivity score summary
Standard turnaround: 2 weeks
Rush timelines available on request. No minimum compound quantity required for feasibility discussion.
Start Your ProjectActivity vs. Endpoint: Know What You're Actually Measuring
Most phosphatase profiling relies on DiFMUP, a generic fluorogenic substrate read at a single endpoint. KinSight measures the full reaction in real time — revealing not just which phosphatases are inhibited, but how and how confidently.
| Features | KinSight | DiFMUP-Based Endpoint Assay |
|---|---|---|
| Measures phosphatase activityActual enzyme velocity on a native-like substrate, not a generic reporter | ✓ | Partial |
| Real-time progress curve per wellFull reaction trajectory, not a single endpoint read | ✓ | – |
| Detects TDI & slow-binding inhibitorsInvisible to endpoint assays | ✓ | – |
| Built-in reaction QC per wellCurve shape reveals artifacts and interference | ✓ | – |
| Low fluorescence interferenceDiFMUP's phenolic fluorophore overlaps many small molecules, inflating false positives | ✓ | – |
| Native phosphopeptide sequencesDerived from authentic phosphosite motifs, not a generic substrate | ✓ | – |
| Expert MOA annotation in reportScientists flag TDI, unusual kinetics, liabilities | ✓ | – |
* "Detects TDI & slow-binding inhibitors" requires a continuous readout by definition — time-dependent inhibition is a kinetic phenomenon that collapses to a single value at any endpoint read. "Measures phosphatase activity (Partial)" reflects that DiFMUP does report enzymatic turnover, but on a generic, non-physiological substrate that does not reflect native phosphosite sequence or charge — inflating potency and masking true selectivity. DiFMUP's single-timepoint format cannot resolve TDI, reversible vs. irreversible inhibition, or reaction QC.
What This Looks Like In Practice
True initial rates, no artifacts
Calculated from the linear region of the curve, before drift or degradation distort the signal.
TDI and slow-binding detection
Time-dependent inhibition shows up as curvature — invisible at a single endpoint.
Native phosphopeptide substrates
Designed around authentic phosphosite motifs — not a generic fluorogenic reporter like DiFMUP.
Kinetic selectivity, not rank order
Distinguishes competitive, slow-binding, and irreversible inhibitors across the panel.
Continuous profiling does more than rank phosphatases by % inhibition.
It reveals whether the assay is linear, curvy, delayed, or time-dependent — that's the difference between data you can act on and data that looks right until it isn't.
Kinase Selectivity Panels
| Panel Name | Panel Size | Substrate Format | Use Case | |
|---|---|---|---|---|
| Full Phosphatase Panel | 48 | Kinetic (PhosphoSens) | Comprehensive off-target screening across Ser/Thr & Tyr phosphatases | View Panel → |
| Custom Panel Design Your Own | 1–48 | Kinetic (PhosphoSens) | Any program-specific target list | Contact Us → |
* Phosphatase selectivity profiling is conducted on a biweekly schedule. Kinetic PhosphoSens assays are used for hit characterization and MOA work; the same assay chemistry converts to PhosphoSens-Red TRF endpoint format for high-throughput library screening. Additional targets can be added upon request.
Don't See the Right Fit?
Work directly with our scientists to design a custom panel around your program's specific targets — any combination of 1–48 phosphatases with the option to add a selection of our 560+ kinases.
Related Services
Kinase Selectivity Profiling
The same continuous-assay approach applied to 560+ serine/threonine and tyrosine kinases — a companion service when off-target kinase liability is part of your program. See kinome profiling →
Time-Dependent Inhibition (TDI) Characterization
Deeper kinetic characterization for compounds showing slow-binding or time-dependent behavior — residence time, kobs, and mechanism-of-inhibition studies beyond a standard panel. See TDI characterization →
Custom Assay Development
Need a target outside our standard catalog? Our team designs and validates a PhosphoSens substrate for it, typically within 8–12 weeks. See custom assay development →
Compound Testing Services
Flexible potency and profiling services scoped to your specific compound and program needs, beyond standard panel formats. See testing services →
Frequently Asked Questions
What is phosphatase selectivity profiling?
Phosphatase selectivity profiling measures how a compound affects the catalytic activity of protein phosphatases across a panel of related enzymes — not just one target in isolation. Because phosphatase active sites can share structural features across families, a compound optimized against one target can retain unwanted activity against others. Profiling maps that activity directly, rather than inferring it from binding alone.
What is a PhosphoSens® phosphatase assay?
PhosphoSens is a continuous, real-time fluorescence assay that tracks phosphatase-catalyzed dephosphorylation as it happens, well by well, rather than reading a single timepoint. It uses substrates built around native phosphosite sequences instead of a generic fluorogenic reporter like DiFMUP, so the signal reflects true catalytic turnover on a physiologically relevant substrate.
How does a continuous phosphatase assay detect time-dependent inhibition (TDI)?
TDI shows up as curvature in the reaction progress curve — inhibition that gets stronger (or weaker) over the course of the assay rather than staying constant. A single-endpoint read collapses that entire trajectory into one number and can't distinguish a fast, reversible inhibitor from a slow-binding or covalent one. A continuous readout captures the shape of the curve, not just where it ends up.
Can't find my target in the catalog?
Reach out directly — our phosphatase panel is actively growing, and many targets not yet listed can still be accommodated through custom assay development. Contact Us Today
How is KinSight different from DiFMUP-based phosphatase assays?
DiFMUP is a generic small-molecule substrate read at a single endpoint — it reports overall phosphatase activity but not on a native-like substrate, and it can't resolve TDI, reaction QC, or true selectivity. KinSight's PhosphoSens assay uses native phosphopeptide substrates and continuous kinetic monitoring, giving you the full reaction trajectory and an MOA read on every well, not just a percent-inhibition value at one timepoint.
Can I design a custom phosphatase panel?
Yes — you can work with our scientists to build a panel around your program's specific targets, choosing any combination from our full phosphatase panel. Contact Us Today
How do you identify off-target liabilities from the data?
Every compound is profiled across the full panel, and results are reported as waterfall plots ranked by percent inhibition alongside the underlying progress curves — so off-target activity is visible both as a ranked signal and as a verifiable kinetic trace, not just a single flagged number.
What does the phosphatase tree visualization show me?
The tree maps your compound's selectivity profile onto the phosphatase family tree, so you can see at a glance whether off-target activity is concentrated within a related subfamily or scattered across unrelated branches — a pattern that's much harder to spot in a table of numbers alone.
Can you profile kinase selectivity as well as phosphatases?
Yes — KinSight's kinome profiling service covers 560+ validated kinases using the same continuous, real-time assay platform. Explore Kinome Profiling
How many compounds can I screen in a single run?
Profiling runs are scheduled biweekly. You can submit multiple compounds per run — contact us to discuss batch sizing, compound requirements (amount, concentration, solvent), and turnaround expectations. Single-compound rush submissions can be accommodated on a case-by-case basis.
Resources for Phosphatase Assay Scientists
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
Kinome Profiling With a Continuous Assay
Have you ever heard of Anscombe’s Quartet? It emphasizes the significance of data visualization and teaches us that descriptive statistics may be misleading.
Profile Your Compound With Confidence
Whether you are confirming a single hit, mapping phosphatome-wide selectivity, or resolving mechanism of action, our team will match the assay format and panel to your program and target constraints.
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