Systematic evaluation of FRAP experiments performed in a confocal laser scanning microscope - Part II: Multiple diffusion processes

A procedure for a systematic evaluation of fluorescence recovery after photo-bleaching (FRAP) data is presented that allows one to determine distributions of diffusion coefficients. The method provides a straightforward and calibration-free way to quantify multiple diffusion processes when FRAP is measured as a function of time and space by means of confocal laser scanning microscopy. It is verified utilizing FRAP experiments on mixtures of differently sized fluorescent micro-spheres as realizations of discrete D distributions.