.jpg?width=450&name=PhosphoSens%20Packaging%20C%20(3).jpg)
Still have questions about our products?
Our scientists can help you choose the right assay format, substrate, and enzyme for your experiment.
About AXL
AXL is a receptor tyrosine kinase (RTK) belonging to the TAM family (Tyro3, AXL, MER), characterized by a unique extracellular domain comprising two immunoglobulin-like and two fibronectin type III repeats. AXL is activated primarily by its high-affinity ligand Gas6 (growth arrest-specific protein 6), a vitamin K-dependent protein, as well as by Protein S, leading to receptor dimerization and trans-autophosphorylation at key residues including Y779 and Y821. Downstream signaling cascades include PI3K/AKT, MAPK/ERK, NF-κB, and JAK/STAT pathways, regulating cell survival, proliferation, migration, and immune modulation. AXL is overexpressed in numerous solid tumors and hematological malignancies, correlating with epithelial-to-mesenchymal transition (EMT), drug resistance, and poor prognosis. Its role in innate immune suppression and tumor immune evasion has elevated AXL as a compelling oncology drug target, driving intense interest in small-molecule inhibitors and antibody-drug conjugates across NSCLC, AML, breast, and pancreatic cancers.
Why PhosphoSens for AXL?
AXL drug discovery presents several assay challenges, including selectivity profiling against closely related TAM kinases (Tyro3, MER) and managing potent covalent or type II inhibitors whose kinetics are poorly captured by endpoint methods. ADP-Glo and HTRF assays measure single fixed timepoints, masking biphasic progress curves and failing to capture covalent inhibitor kinact/KI parameters critical for AXL programs. Radiometric assays introduce handling complexity and waste disposal burdens. AssayQuant's PhosphoSens continuous fluorescent kinase assay monitors AXL substrate phosphorylation in real time at physiological ATP concentrations, generating full progress curves that directly reveal mechanism-of-inhibition, time-dependent inhibition, and accurate IC50 values. This enables robust covalent inhibitor characterization, reduces assay artifacts from product inhibition, and accelerates SAR cycles with higher data quality across AXL inhibitor campaigns.
Key Pathways:
PI3K/AKT signaling
MAPK/ERK signaling
JAK/STAT signaling
Epithelial-to-Mesenchymal Transition (EMT)
Talk to a Scientist
Have questions about AXL assay design, selectivity panels, or covalent inhibitor characterization?
Ask Our Scientists →
How pricing works:
Select a kit or substrate below, then request a quote. Bundle discounts apply automatically.
Select a kit or substrate below, then request a quote. Bundle discounts apply automatically.
Real-Time AXL Activity Assays
Continuous, real-time fluorescent assays optimized for quantitative AXL activity measurements, IC50 determination, and mechanistic studies.
Assay Format: Continuous kinetic fluorescence (real-time)
PhosphoSens-Kinetic assays directly quantify enzyme activity by continuously monitoring substrate phosphorylation or dephosphorylation in real time, generating a full progress curve in every well.
Learn more about PhosphoSens-Kinetic →Need pricing or availability? Select a kit or substrate to request a quote below.
Kits
PhosphoSens-Kinetic Kinase Activity Kit - AQT0794
Ready-to-use assay kits containing substrate and all essential reagents.
Kit Contents
- Optimized PhosphoSens® substrate (AQT0794)
- ATP, DTT, EGTA, Reaction Buffer & Dilution Buffer
Automatically save 10% when bundling 10ug recombinant enzyme with your 1,000 assay kit. View enzymes
Price: $425
Substrate
PhosphoSens Kinase Substrate AQT0794
Bulk PhosphoSens® substrate for assay development and high-throughput workflows.
Specifications
Automatically save 10% when bundling Reagent Packs with your substrate. View Reagent Packs
Price: $2795
Ready to request pricing for AXL?
Select a kit, substrate, or enzyme above. Our team will confirm pricing, availability, and any applicable bundle discounts.
Request a QuoteTRF AXL Screening Assays
Robust endpoint TRF assays optimized for high-throughput screening and quantitative AXL activity measurement in plate-based workflows.
Assay Format: Time-resolved fluorescence (TRF, endpoint)
PhosphoSens-Red assays use europium-based time-resolved fluorescence detection to enable robust, plate-based quantification of enzyme activity, making them well suited for high-throughput screening workflows.
Learn more about PhosphoSens-Red →Need pricing or availability? Select a kit or substrate to request a quote below.
Kits
PhosphoSens-Red Kinase Activity Kit - AQT0653
Ready-to-use TRF assay kits containing substrate and essential reagents.
Kit Contents
- Optimized PhosphoSens® substrate (AQT0653)
- ATP, DTT, EGTA, Reaction Buffer & Dilution Buffer
- Europium Detection Solution
Automatically save 10% when bundling 10ug recombinant enzyme with your 1,000 assay kit. View enzymes
Price: $455
Substrate
PhosphoSens Kinase Substrate AQT0653
Bulk substrate for PhosphoSens-Red TRF assays and high-throughput workflows.
Specifications
Automatically save 10% when bundling Reagent Packs with your substrate. View Reagent Packs
Price: $2795
Ready to request pricing for AXL?
Select a kit, substrate, or enzyme above. Our team will confirm pricing, availability, and any applicable bundle discounts.
Request a QuoteActive Recombinant Enzymes for AXL
Wild-type and mutant forms of AXL for assay development, kinase profiling, and mechanistic studies. Enzymes are supplied active and optimized for PhosphoSens® substrates.
AXL, Active
Human • Baculovirus-Insect Cells
Technical Specifications
- Catalog: AQT-A34-11G
- Species: Human
- Expression System: Baculovirus-Insect Cells
- Storage Buffer: Supplied as sterile 50 mM Tris-HCl, pH 7.5, 50-300mM NaCl, 10mM glutathione, 0.1mM EDTA, 0.25-1.0mM DTT, 0-0.1mM PMSF, 10-25% glycerol
- Molecular Weight: ~78 kDa
- Purity/Activity: For specific information on a given lot, see related technical data sheet.
- Storage Conditions: Store product at -70°C. For optimal storage, aliquot target into smaller quantities after centrifugation and store at recommended temperature. For most favorable performance, avoid repeated handling and multiple freeze/thaw cycles.
Available Sizes:
Price: $$348.00
Request a QuoteFrequently Asked Questions: AXL Assays
Why is continuous kinetic monitoring important for AXL inhibitor characterization?
AXL programs increasingly involve time-dependent and covalent inhibitors whose mechanistic parameters, including kinact and KI, cannot be resolved from single-timepoint endpoint assays. PhosphoSens continuous assays generate complete progress curves in real time, enabling accurate mechanistic classification and kinact/KI determination without additional assay development. This provides richer SAR data and reduces the risk of misclassifying inhibitor mechanism during lead optimization.
Can PhosphoSens assays differentiate AXL from closely related TAM kinases Tyro3 and MER?
Yes. AssayQuant offers substrate peptides and assay conditions optimized for individual TAM family members, allowing direct selectivity profiling of AXL inhibitors against Tyro3 and MER in matched assay formats. Running parallel continuous kinetic assays under identical ATP and buffer conditions eliminates format-driven artifacts and provides reliable selectivity ratios critical for TAM-selective drug discovery programs.
What ATP concentration is used in AssayQuant's AXL PhosphoSens assay?
AssayQuant's PhosphoSens assays are configured at or near the physiological ATP concentration (approximately 1 mM), ensuring that IC50 values reflect biologically relevant potency rather than artificially low values generated under ATP-limiting conditions common in ADP-Glo or HTRF formats. Physiological ATP also allows accurate competitive inhibitor characterization and meaningful translation of biochemical potency to cellular and in vivo studies.
Data & Resources
Explore data and documents to support your kinase and phosphatase experiments. Download sample data, protocols and other resources to see how our assays perform and to help you get started in your own lab. All validation data generated using PhosphoSens® assays under recommended conditions.
Sample Report: AQT0734 - EGFR Assay Validation Report
Each validation report provides experimental conditions and data showing:
- Enzyme titration and linearity
- Sensor peptide substrate titration and Km determination
- ATP titration and Km determination
- DMSO titration and assay tolerance
- Inhibitor titration and IC50 determination
Protocol
Inhibitor IC50 Protocol
See how the PhosphoSens-Kinetic Assay can be used to find the IC50 of a kinase inhibitor.
Download Protocol →Webinar
Webinar: Continuous Assay Validation
Discover how continuous assay formats power deep understanding of kinase function. See how PhosphoSens® assays guide inhibitor profiling, selectivity assessment, and mechanistic characterization.
Watch the Webinar →Service
KinSight™ AXL Profiling
Need broader selectivity data? KinSight profiling runs your compounds across our full kinase panel under identical PhosphoSens conditions.
Learn about KinSight →Stay Informed
Want to hear the latest about our technology? Be among the first to learn about our latest products and services.