FLUORESCENCE RECOVERY AFTER PHOTOBLEACHING OF SUSPENSIONS OF VACUOLES

In this work we derive theoretical expressions for the FRAP measured o n a liquid suspension of vacuoles labelled by a fluorescent probe boun d to the surface membrane of these vacuoles. The bleaching laser beam creates an inhomogeneity in the surface concentration of the probe mol ecules. We consider the case in which the randomization of these probe molecules on the vacuole surface occurs much faster than the fluoresc ent recovery due to the vacuole diffusion. For a given value of the bl eaching parameter K, we found that the bleaching fraction of the fluor escent molecules and the fluorescence recovery rare are decreasing fun ctions of the square ratio of the vacuole to the laser beam radius of the FRAP instrument.