Quantitative imaging of protein–protein interactions by multiphoton fluorescence lifetime imaging microscopy using a streak camera

Fluorescence lifetime imaging microscopy (FLIM) using multiphoton excitation techniques is now finding an important place in quantitative imaging of protein-protein interactions and intracellular physiology. Recent developments in multiphoton FLIM methods are reviewed and a novel multiphoton FLIM system using a streak camera is described. An example of a typical application of the system is provided in which the fluorescence resonance energy transfer between a donor-acceptor pair of fluorescent proteins within a cellular specimen is measured.