Wide-field fluorescence lifetime imaging with multi-anode detectors.

Fluorescence lifetime imaging microscopy (FLIM) has become a powerful and widely used tool to monitor inter- and intramolecular dynamics of fluorophore-labeled proteins inside living cells.Here, we present recent achievements in the construction of a positional sensitive wide-field single-photon counting detector system to measure fluorescence lifetimes in the time domain and demonstrate its usage in FRET applications.The setup is based on a conventional fluorescence microscope equipped with synchronized short-pulse lasers that illuminate the entire field of view at minimal invasive intensities, thereby enabling long-term experiments of living cells. The system is capable to acquire single-photon counting images and measures directly the transfer rate of fast photophysical processes as, for instance, FRET, in which it can resolve complex fluorescence decay kinetics.