Measuring Protein Function in Biologically Relevant Models

The more biologically relevant your model, the better your predictions. Our solutions help you get more relevant answers from plate-based screens through organoids to whole-animal studies.

Get Biologically Relevant Answers From Plate to Animal

Every assay is a simplification. The question is how much biology you're willing to trade for convenience.

Your protein of interest doesn't live in a tube. It lives in a cell, shaped by its environment in ways no isolated system can replicate. Move into 3D models and you recover the gradients and matrix interactions that govern how compounds penetrate tissue and cells respond. Take it in vivo, and you finally see the pharmacological behavior that determines whether a mechanism becomes a medicine.

We offer solutions built to travel that entire path — sensitive enough to detect proteins at endogenous expression levels, compatible with spheroid and organoid workflows, and bright enough to image in a living animal. The same portfolio of reporters, from a 384-well plate to a whole animal.

Featured Solutions

CRISPR-Edited Cell Models

Endogenous tagging with HiBiT, NanoLuc or HaloTag for physiologically relevant expression

Cell-Based Assays Using NanoLuc® Technology

Monitor live-cell target engagement, PPIs, and protein dynamics

3D & Organoid Models

Measure cell health, metabolism and expression in advanced in vitro cultures

In Vivo Imaging

Bioluminescent and fluorescent imaging in whole, living organisms

Frequently Asked Questions

What are the top methods for measuring protein interactions in living cells for drug discovery versus basic research?

For drug discovery, NanoBRET® Technology is the recommended choice for target engagement, PROTAC ternary complex confirmation, and GPCR pharmacology in intact living cells. For basic research, NanoBiT® Technology measures PPI assembly and dissociation kinetics in real time with a standard luminescence plate reader.

What are the pros and cons of fluorescent vs. luminescent-based products for detecting protein interactions in live cells?

Fluorescent approaches integrate well with imaging workflows, specifically working well for spatial information. They can, however, suffer from autofluorescence interference at low expression levels. Bioluminescent tools like NanoBiT and NanoBRET eliminate autofluorescence entirely and enable detection at physiological expression levels, though they capture population-level signal rather than spatial information without a luminescence-capable microscope.

Which live-cell protein interaction detection kits are best for screening drug libraries and how do they compare on cost?

NanoBRET® Assays are purpose-built for screening: they run in 96- or 384-well plates, require no lysis, and produce a ratiometric output that normalizes for cell number variation across wells. Per-well costs are primarily driven by substrate usage; contact your Promega representative for current pricing by plate format.

Which method should I use if I want to track an endogenous protein without overexpressing it?

HiBiT CRISPR knock-in inserts an 11-amino acid tag at the native locus using a short oligo donor, enabling quantitative luminescent detection at true endogenous expression levels. HaloTag knock-in is preferred when subcellular localization or trafficking is the primary question.

What are the top reagents for studying endogenous protein degradation and how do they compare?

The Nano-Glo® HiBiT Lytic Detection System provides a simple, high-sensitivity endpoint readout, while Nano-Glo® Extended Live Cell Substrate (Endurazine) enables real-time kinetic monitoring in intact cells. Pairing either with a NanoBRET® Ternary Complex Kit adds mechanistic confirmation that the degrader is engaging both target and E3 ligase upstream of the degradation readout.

Which methods are best for measuring endogenous membrane protein distribution?

Janelia Fluor® HaloTag® Ligands are the best suited for spatial studies, with spectral options from yellow-orange through far-red supporting multiplexed live-cell imaging. The Nano-Glo® HiBiT Extracellular Detection System complements this by quantifying surface-accessible protein abundance in live cells, making it well-suited for tracking receptor internalization.

Featured Resources

Measuring Protein Function in Biologically Relevant Models

Get Biologically Relevant Answers From Plate to Animal

Featured Solutions

CRISPR-Edited Cell Models

Cell-Based Assays Using NanoLuc® Technology

3D & Organoid Models

In Vivo Imaging

Frequently Asked Questions

Featured Resources

Imaging

Kinetic Cell-Based Assays

FAQ: HiBiT-based CRISPR Knock-In

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