Drug Discovery Keeps Moving.
Your Targets Stay in Reach.
Proven across target classes. Ready for your next one.
The question at the center of drug discovery has never changed: does this compound actually engage its target, in a living cell, in a way that matters? What has changed is the complexity of what answering that question requires. Find what your program needs and discover what else is within reach.
NEW TarSeerâ„¢ BRETSAâ„¢ Target Engagement brings challenging targets within reach by revealing true engagement inside living cells.
Featured Article
"One Question, Every Target:
The Evolution of Small Molecule Drug Discovery"
The clean compound that disappoints in cells may be telling you something real. The degrader result that looks like one failure may be several. From kinases to the undruggable frontier, a look at how each new class of targets changed what it takes to prove a compound actually works.
Which target class is your program focused on?
Every program is defined by its target. The biology and the measurement challenges differ—so do the tools. We've built deep coverage across the target classes driving modern drug discovery, from the most well-characterized to the most recently emerged.
Kinase Biology
High-throughput biochemical and cellular assays to study kinase binding and inhibition
GPCR Research
Measure the response at each step of the G-protein coupled receptor (GPCR) signaling cascade.
RAS Pathways
Assays and technologies to facilitate RAS drug discovery
PARP and DDR
Assays and technologies to facilitate PARP/DDR pathway drug discovery
Inflammasome Activation
Assays and technologies to monitor inflammasome activation in live cells
Don't see your target class? We can build custom assays for targets that don't have an off-the-shelf solution yet. Explore Services & Support
What type of assay does your experiment call for?
The right assay depends on what question you're asking and where you are in your program. We offer tools across the full target-based discovery workflow: from biochemical activity and cell viability to live-cell target engagement, protein-protein interactions and beyond. Each is built to generate data you can act on.
| Assay Type | What It Measures | Best For | Featured Solutions |
|---|---|---|---|
| BIOCHEMICAL ASSAYS | |||
| Enzyme Activity Assays | Enzyme activity and compound potency in purified systems; establishes biochemical ICSD | Hit identification and compound ranking in early discovery; HTS-compatible | ADP-Gloâ„¢, Methyltransferase-Gloâ„¢, GTPase-Gloâ„¢ |
| Biochemical Protein Interaction Assays | Protein-protein and protein-small molecule binding in purified systems; ternary complex formation | HTS-compatible screening of PPI modulators and degrader ternary complex assembly | Lumit® Anti-Tag Protein Interaction Reagents |
| CELLULAR TARGET ENGAGEMENT & BINDING | |||
| NanoBRET® Target Engagement Assays | Direct compound-target binding in intact living cells; intracellular affinity, fractional occupancy and residence time | Confirming cellular target engagement across 400+ validated targets including kinases, RAS/RAF, E3 ligases and epigenetic targets | NanoBRET® TE Assays |
| TarSeer® BRETSA™ Target Engagement | Compound-induced changes in target protein thermal stability in living cells; tracer-independent | Poorly characterized or difficult targets with no known ligands or established assays; targeting novel binding sites | TarSeer® BRETSA™ (Early Access) |
| CELLULAR ACTIVITY ASSAYS | |||
| Cellular Protein Interaction Assays | PPI formation, disruption, or stabilization in living cells in real time | Programs where binding partners drive the mechanism; PPI stabilizers and disruptors; degrader ternary complex studies | NanoBiT® PPI Assays, NanoBRET® PPI Assays |
| Secondary Messenger Assays | Intracellular second messenger levels in response to compound treatment | GPCR programs; innate immune pathway activation; downstream signaling confirmation | cAMP-Glo™, GloSensor® cAMP, Lumit® cGAMP |
| Reporter Gene Assays | Transcriptional pathway and promoter/response element activation | Measuring pathway-level compound response; kinase, RAS/MAPK, NF-κB and other transcriptional programs | ONE-Glo™, Nano-Glo® Luciferase Assay System, Nano-Glo® DLR |
| Protein Phosphorylation Assays | Signaling pathway activation via key effector phosphorylation | Measuring kinase pathway response and downstream signaling | Lumit® Immunoassay Cellular System |
| Target Protein Expression & Localization | Target protein abundance, stability and degradation in living cells; subcellular localization | Degrader compound characterization; protein trafficking studies; endogenous target expression in physiologically relevant models | HiBiT Tagging & Detection Systems, Lumit® Immunoassay Cellular System, HaloTag® and Fluorescent Ligands |
| CELLULAR PHENOTYPIC ASSAYS | |||
| Cell Health Assays | Cell viability, cytotoxicity and apoptosis in response to compound treatment | Confirming on-target cell killing in oncology; assessing compound-induced cytotoxicity; establishing therapeutic window | CellTiter-Glo®, LDH-Glo™, Caspase-Glo® 3/7 |
| Cytokine Assays | Secreted cytokine levels as indicators of immune activation or inflammatory response | Immunology programs; assessing compound effects on immune cell phenotype | Lumit® IL-2, Lumit® TNF-α, Lumit® IFN-γ |
| Energy Metabolism Assays | Cellular metabolic state including NAD/NADH balance, glucose uptake, lipid levels and more | Assessing metabolic liabilities and compound effects on cellular energy status | NAD/NADH-Gloâ„¢, Glucose-Gloâ„¢, Triglyceride-Gloâ„¢ |
Detection instrument: The GloMax® Discover System reads luminescent and fluorescent output across every assay type above—one detection platform across the SMDD workflow. View GloMax® Instruments
Genomic Analysis
Reliable genomic and proteomic analysis tools underpin every stage of drug discovery, from identifying and validating targets before a screening campaign to confirming compound mechanism downstream. We offer both manual and automated nucleic acid extraction and purification solutions for high-quality DNA and RNA from a broad range of sample types, scaling from single-prep manual kits through benchtop automation to high-throughput platforms. These workflows support gene expression profiling, CRISPR cell line confirmation, target validation and downstream amplification and quantitation.
Proteomic Analysis
For mass spectrometry-based proteomics, we offer a comprehensive sample preparation portfolio spanning proteases, glycosidases and reagents for instrument performance monitoring—including MS-grade enzymes such as Trypsin/Lys-C Mix, Arg-C Ultra and rChymoSelect™. Together, these tools support proteomic target validation, degrader substrate profiling, PTM analysis and biomarker workflows.
Which modality is your program built around?
How a compound works - not just what it targets - shapes your assay decisions. Each modality comes with its own measurement challenges and its own set of tools. The assays described above were developed to support small molecule agonists, antagonists, and reversible inhibitors across diverse target classes, some of which are described on this page. As the field has expanded into new modalities, so have our tools. Below are a few of the emerging modalities we're actively building for - a spotlight, not the full extent of what we support.
PROTACs, molecular glues and degraders don't work like traditional inhibitors, and the assays that characterize them reflect that. NanoBRET® PROTAC TE assays and HiBiT-based degradation quantification are the core tools for ternary complex formation, degradation quantification and live-cell confirmation. View Targeted Protein Degradation Tools
The biology spans expression modulation, RNA-protein interactions and epitranscriptomics—the measurement approach has to follow. CRISPR-HiBiT cell lines, NanoBRET® binding assays and bioluminescent reporter systems cover the core challenges. View Targeting RNA Resources
Track internalization efficiency, Fc effector function, payload cytotoxicity and target cell specificity, often across the same set of experiments. From pHAb dyes and internalization bioassays to real-time cytotoxicity and HiBiT target cell killing, the coverage spans the full development workflow. View ADC Resources
Working in a modality you don’t see here? These are just a few we’re highlighting—our drug discovery team develops and adapts tools across many more, including traditional inhibitors. Explore Services and Support
Need tools that don't exist yet for your target? We can build them.
Not every target has an assay waiting for it. Our drug discovery team works directly with you to develop what doesn't exist yet—from custom assay development and compound potency testing to CRO support. Wherever your program is, we can help.
Compound Screening
Compound potency testing and screening services using the same quantitative live-cell platform your lab already relies on.
CRO Support
Working with a CRO? We support them directly—tools, materials, and licensing so your assays translate seamlessly into their workflows.
Assay Development
Custom assay development for targets that lack off-the-shelf solutions—including target engagement assays for new targets and cell line engineering.
Working with a target that doesn't have an assay yet?
Frequently Asked Questions
Biochemical enzyme activity assays establish IC50 and rank compounds in early discovery, where speed and scale matter most. Options include ADP-Glo™, Methyltransferase-Glo™, and GTPase-Glo™, spanning kinases, methyltransferases, GTPases, and other enzyme classes. These assays are fast, HTS-compatible, and precise about what they measure, a starting point for the cellular work that follows. For protein-protein and protein-small molecule interactions in purified systems, Lumit® Anti-Tag Protein Interaction Reagents provide homogeneous, no-wash detection scalable to high-throughput formats.
NanoBRET® Target Engagement assays use bioluminescence resonance energy transfer to detect direct binding between a compound and its target inside intact cells. Unlike biochemical methods, live-cell measurement captures the intracellular conditions that determine whether a candidate will work in a physiologically relevant context: compound permeability, competing endogenous factors and true intracellular affinity. With over 400 validated assays across kinases, E3 ligases, epigenetic targets, RAS/RAF and more, NanoBRET® TE supports both equilibrium and kinetic characterization of compound-target interactions.
Targeted protein degradation and induced-proximity mechanisms need readouts biochemical assays weren't built for: ternary complex formation, degradation quantification and live-cell confirmation of mechanism. NanoBRET® PROTAC TE assays measure compound engagement with both the target protein and the E3 ligase in living cells. HiBiT-based degradation assays provide quantitative, kinetic readouts of target protein levels, tracking degradation as it happens rather than at a single endpoint. For programs where the ternary complex itself is the mechanism, NanoBiT® and NanoBRET® PPI assays detect complex formation, disruption and stabilization in real time.
A key bottleneck in AI-driven drug discovery is data quality. Models are only as good as the measurements they learn from, and noisy or context-poor data limits what they can predict. Quantitative, reproducible, cell-based assays provide the high-confidence inputs these workflows depend on: NanoBRET® TE for target engagement, HiBiT-based systems for degradation kinetics, and bioluminescent cell health assays for phenotypic readouts. Where AI nominates a target with no established assay, TarSeer™ BRETSA™ TE extends measurement to poorly characterized proteins without requiring a target-specific tracer.
Poorly characterized and difficult targets, those without known ligands, established assays, or a defined binding site, often resist conventional approaches. TarSeer™ BRETSA™ measures target engagement in living cells without a target-specific tracer, which suits targets that have been hard to assay by other means. For targets amenable to tagging, HiBiT and NanoBRET® approaches add degradation and engagement readouts in a cellular context. Where no off-the-shelf method fits, our drug discovery team develops custom assays. Not every target is tractable by every approach, and part of the conversation is finding the one that fits your biology.
Target-based drug discovery requires tools across the full workflow: activity assays to establish biochemical potency, cellular assays to confirm target engagement and pathway response and cell health assays to assess compound tolerance. The right combination depends on the target class and where your program sits in its progression. We offer solutions spanning kinases, GPCRs, RAS, DNA damage response, induced proximity, and emerging target classes, whether your target is well-characterized or biology that hasn't been fully mapped yet.
Cellular and phenotypic assays show whether a compound is affecting cell function and triggering the biological response you're after. Reporter and secondary-messenger assays read pathway-level response, phosphorylation assays track signaling, and cell health assays (CellTiter-Glo®, LDH-Glo™, Caspase-Glo® Assays) measure viability, cytotoxicity, and apoptosis. In oncology, these readouts confirm a compound is killing the intended cells; elsewhere, they flag unintended toxicity. Together, they tell you not just that a compound binds, but what it does.
Start a Conversation
Tell us about your target and your program. Our drug discovery team reviews every inquiry and routes it to the right specialist—whether that's assay selection, custom development or a technical question about your biology.