Real-Time Kinase Activity Assays for Drug Discovery
Direct, continuous measurement of kinase activity across 500+ validated targets. Purpose-built for IC₅₀ determination, selectivity profiling, TDI characterization, and mechanistic studies.
PhosphoSens® technology generates a full activity progress curve in every well — not a single-point estimate. That means higher-confidence kinetics, fewer repeat experiments, and assay data you can build on.
500+
Validated Kinase Targets
2
Assay Formats & Sample Types
96/384/1536
Well Plate Compatible
NCI Funded
MIT-licensed technology
Choose the Format That Fits Your Research
Not all kinase assays are built the same. Select the format that matches how you work — in-house kits or a fully managed CRO service.
PhosphoSens-Kinetic
Generates a full activity progress curve in every well. Ideal for IC₅₀, Kᵢ, kobs, TDI, and mechanistic characterization. No endpoint assumptions.
PhosphoSens-Red
Higher throughput, compatible with standard plate readers. Excellent for hit validation, IC₅₀ screening, and selectivity campaigns across large compound libraries.
Need a CRO to run it?
KinSight™ profiling services run your compounds against our 400+ kinase panel. You receive annotated kinetic reports with TDI flags and MOA insights — in two weeks.
Not Sure Which Assay Fits Your Target?
Tell us your target and research application and we'll point you to the right assay format, substrate, and enzyme. No obligation — just a faster path to the right kit.
Why Researchers Choose PhosphoSens® Over Endpoint Methods
Most kinase assays give you a single data point at a single moment in time. PhosphoSens generates a continuous activity trace — so you see the full kinetics, not just a snapshot.
True initial rates, no artifacts
Calculate rates from the true linear region of the progress curve — free from lag phase, substrate depletion, or enzyme instability artifacts.
Detect TDI and slow-binding inhibitors
Capture time-dependent mechanisms — TDI, slow-on/slow-off, irreversible binding — that endpoint assays miss entirely.
Physiologically relevant conditions
Compatible with physiological ATP, Mg²⁺, Mn²⁺, and Ca²⁺. Validated substrates with defined phospho-acceptor sites — no antibody cross-reactivity.
| Platform | Measures activity directly | Detects TDI & slow‑binding inhibitors | Real-time continuous readout | Detects all inhibitor types |
|---|---|---|---|---|
| AssayQuant PhosphoSens® | ||||
| Luminescent assayse.g. Kinase-Glo, ADP-Glo | ||||
| Radiometric assayse.g. ³³P/³²P filter binding | ||||
| Mobility shift assayse.g. Caliper EZ Reader | ||||
| Competition bindinge.g. KINOMEscan, KdELECT |
✓ Supported | Indirect = proxy readout, endpoint assumptions apply | ✗ Not supported
Read: Continuous vs. Endpoint Kinase Assays →Kinase Activity Directly From Cell Lysates
Skip the purified enzyme. PhosphoSens-Lysate assays measure kinase activity in native cellular context — capturing the biology your recombinant assays can't.
Continuous Phosphatase Activity Assays
The same real-time, direct measurement you rely on for kinases — now for phosphatases. 50+ validated targets, same PhosphoSens® platform.
Explore 500+ Validated Kinase Assay Targets
Search by gene symbol, target family, or indication. Each target page includes available formats, substrates, enzymes, pricing, and application notes.
PhosphoSens-Kinetic Product Catalog
For your convenience, you can also download a PDF version to review later or share with your colleagues.
DownloadResources for Kinase 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
PhosphoSens-Kinetic Phosphatase Inhibitor IC50 Determination
Frequently Asked Questions
Your pain? We understand. This is why we do what we do, and can provide you with an experience like no other.
What is a PhosphoSens® kinase assay?
PhosphoSens® assays are continuous, real-time kinase activity assays that directly measure phosphorylation of a substrate peptide throughout the reaction. Unlike endpoint assays that capture a single time point, PhosphoSens generates a full progress curve — enabling true kinetic analysis including IC₅₀, Kᵢ, kobs, and time-dependent inhibition (TDI) from a single experiment.
What's the difference between PhosphoSens-Kinetic and PhosphoSens-Red?
PhosphoSens-Kinetic is a continuous fluorescence assay that monitors kinase activity in real time throughout the reaction, generating full progress curves. PhosphoSens-Red is a time-resolved fluorescence (TRF) endpoint format optimized for higher throughput screening. Both use the same underlying PhosphoSens® substrate technology — the choice depends on whether you need kinetic depth (Kinetic) or screening throughput (Red).
How does a continuous kinase assay detect time-dependent inhibition (TDI)?
TDI compounds produce a characteristic change in the progress curve shape — the inhibition deepens over time as the compound slowly occupies or covalently modifies the enzyme. Because PhosphoSens monitors activity continuously, this curve deviation is directly visible. Endpoint assays that measure at a single time point will either miss TDI entirely or mischaracterize its potency, depending on when they sample the reaction.
What plate reader is required for PhosphoSens assays?
PhosphoSens-Kinetic assays require a standard fluorescence plate reader capable of kinetic reads (repeated measurements over time) with excitation/emission appropriate for the Sox fluorophore. PhosphoSens-Red assays require a time-resolved fluorescence (TRF) reader. Most modern multimode readers in drug discovery labs are compatible. Contact us if you need compatibility confirmation for your specific instrument.
Can't find my target in the catalog?
We offer custom assay development for kinase targets not currently in our catalog. Our team can design and validate a PhosphoSens substrate for your target, typically within 8–12 weeks. Contact us to discuss your target, timeline, and project requirements.
Ready to Characterize Your Compound?
Talk to one of our scientists about your target, your workflow, and which assay format will get you the data you need.
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