<title>Novel photobleaching model in living cells</title>

A novel photobleaching model was proposed, in which a D-P photobleaching mechanism was developed. By combining with the conventional D-D and D-O photobleaching mechanisms, the dependence of photobleaching rate on the excitation power is well illustrated. The validity of this model was demonstrated with GFP photobleaching experiments in cases of one-photon excitation (1PE) and two-photon excitation (2PE) respectively. Previously inexplicable experimental results published in literature were also illustrated with this new model.