Fluorescence lifetime imaging endoscopy

We present two FLIM endoscopes for clinical imaging and in vivo cell biology. For subcellular confocal imaging we demonstrated the first confocal FLIM endomicroscope, implementing TCSPC with a Cellvizio®GI, which we have now developed as a self-contained wheeled instrument (1.0 × 0.7 m) incorporating a tunable excitation laser and acquiring images in < 10 s. This has been applied to image FRET in live cells and to image tissue autofluorescence, for which we are implementing "FIFO" for image montaging. For diagnostic screening/guided biopsy, we have developed a complementary wide-field FLIM endoscope employing time-gated detection with violet and UV excitation for imaging over mm-cm fields of view.