Lukyanov, K. A., Chudakov, D. M., Lukyanov, S., and Verkhusha, V. V.
Innovation: Photoactivatable fluorescent proteins.  Nature Reviews Molecular Cell Biology 6: 885-891 (2005).

The fluorescence characteristics of photoactivatable proteins can be controlled by irradiating them with light of a specific wavelength, intensity and duration. This provides unique possibilities for the optical labeling and tracking of living cells, organelles and intracellular molecules in a spatio-temporal manner. Here, we discuss the properties of the available photoactivatable fluorescent proteins and their potential applications.