BRET measurement on CCD camera-based microtiter plate readers

NanoBRET assays, which utilize bioluminescence energy resonance transfer (BRET), have been widely adopted in drug discovery for measuring both protein-protein interactions and drug target engagement. While the EnVision and other traditional well-scanning plate readers that measure a single well at a time are satisfactory for signal detection for smaller experiments, it becomes challenging to scale these assays to applications that require higher throughput. To address this, we explored the adaptation of the ViewLux and FLIPR plate readers for measuring NanoBRET signal. These plate readers utilize charge-coupled device (CCD) cameras for detection, which enable imaging of the entire assay plate simultaneously. We used tool compounds to generate data from each plate reader and found that the image-based plate readers can be used to measure NanoBRET signals with high S/B and Z´, resulting in comparable IC 50 values to those obtained from the EnVision, while requiring less time to complete reads. Consequently, utilization of image-based plate readers for NanoBRET measurement may enable applications that require faster reads, such as for high-throughput screening or kinetics studies.