Cell images from standard acceptor photobleaching FRET.

(A–C) Cos-1 cells transfected with plasmids encoding the CFP-YFP fusion proteins as indicated. (D) Representative cells transfected with empty vectors as a negative control for FRET. The white boxes indicated CFP and YFP images before and after photobleaching by a high intensity argon laser light. Five ROIs were analyzed for each cell and at least 5 cells were quantified from three different experiments. (E) FRET efficiencies calculated with Leica LAS AF software during YFP photobleaching. All data are represented as mean±S.D. *, P<0.05 compared to untransfected Cos-1 cells.