A reversibly photoswitchable GFP-like protein with fluorescence excitation decoupled from switching

To overcome the limitations of the photoswitchable fluorescent proteins commonly used, this paper describes the discovery of a GFP-like protein for which different wavelenghts are used to generate the fluorescence emission and to switch the fluorescent states of the protein. After mutagenesis studies on Citrine, the authors found a protein that can be reversibly photoswitched from a fluorescent state by UV irradiation at 365 nm, to a non-fluorescent state by irradiation at 405 nm and the fluorescence is excited at 515 nm.

To illustrate the applications of their optimized protein, the authors realized a PacMan movie, by assembling 33 images representing 33 switching cycles.