Dimming the donor to brighten up FRET-based biosensors.

The current biosensors based on Forster resonance energy transfer (FRET) lack good anisotrophy-based indicators for detecting rotational changes triggered by analyte-binding. Laskaratou et al. developed a FRET-induced Angular Displacement Evaluation via Dim donor (FADED) tool to expand the existing toolkit. With less bleed-through from a donor with dim fluorescence, the changes in acceptor anisotropy signals of these tools could readily indicate cytosolic calcium dynamics.