Promega Corporation is launching a new live cell target engagement platform that could close a long-standing gap between biochemical and cellular assays for unstudied or difficult-to-investigate proteins. The TarSeer™ BRETSA™ The Target Engagement System is a novel energy-shift-based bioluminescence resonance assay for detecting ligand-protein interactions in intact cells using protein denaturation. It provides drug discovery researchers with early cellular insights into specific targets, validating weak or early chemistry and expanding the targets accessible to live cell drug discovery workflows. The technology will debut at the Society for Laboratory Automation and Screening (SLAS) International Conference and Exhibition in Boston, February 7-11, 2026.
Now you can potentially study intracellular target binding for any protein in living cells. This platform will give drug discovery researchers new starting points to pursue a vast fraction of previously elusive therapeutic targets within the human proteome.”
Matt Robers, Associate R&D Director, Promega
Drug discovery teams can identify biochemical hits that fail to translate into cellular environments. Lacking target-specific cellular assays, especially for difficult or intractable targets, lead validation and optimization is a dead end. BRETSA is designed to help overcome this challenge by measuring compound binding to target proteins directly in cells through changes in the thermal stability of the target protein, even when the targets do not have known chemical probes or the binding pockets are not well defined. This early cellular characterization of target ligand potency reduces uncertainty and increases initial stage confidence in compound prioritization.
Advantages of TarSeer™ BRETSA™ The Target Engagement system includes:
- Increased sensitivity: Researchers can measure compound potency and binding across classes in living cells, including weak interactions that are difficult to quantify or even missed in early discovery.
- Wide Application: The platform has been applied to more than 20 target classes and multiple cellular compartments, supporting studies of proteins lacking established cellular assays.
- Flexible, scalable workflow: An add-only workflow compatible with 96- and 384-well formats allows groups to scale from focused monitoring to higher-throughput experiments.
Matt Robers will introduce the platform and present data on several classes of targets during a podium presentation titled “BRETSA: A Highly Sensitive, Broadly Applicable BRET Method for Measuring Target Binding by Protein Denaturation in Live Cells” at SLAS 2026. The talk will take place at 3:30 p.m. on Tuesday, February 10, Boga2 staff will be available throughout the conference at Prome26. #1448 to discuss the technology.
The TarSeer™ BRETSA™ The Target Engagement System builds on the longstanding success of Promega NanoBRET® Target Engagement System, which also uses BRET to quantify moving target engagement. The BRETSA platform complements NanoBRET methods by addressing targets that lack suitable probes for NanoBRET analysis. By expanding this toolbox, Promega is deepening its support for researchers developing small molecule drugs against a wide range of disease-related proteins.
Video credit: Promega Corporation
