Single Molecule Fluorescence Resonance Energy Transfer (smFRET) in Live Cells

This research reports progress towards single molecule fluorescence resonance energy transfer (smFRET) in the cytoplasmic environment of live cells. Recombinantly expressed, externally dye-labeled SNARE proteins were microinjected into cultured cells, tracked and imaged to observe real-time conformational dynamics. We discuss the many obstacles lowering signal:noise \textit{in vivo} (cellular and coverslip autofluorescence, dye photobleaching) and our methods for overcoming these obstacles. Initial findings and the implications for this technique will also be discussed.