Molecular discrimination using fluorescence recovery after photobleaching

Abstract

In this paper we analyzed single and multiplecomponent diffusion through Monte Carlo simulation of Fluorescence Recovery after Photobleaching (FRAP). For the single-component model, it was observed that as the mean free path (mfp) was increased, fluorescence recovery was faster but the maximum intensity achieved was lower compared to shorter mfps. It was also observed that a twofold increase in mfp corresponds to an exponential decrease in the characteristic diffusion time τ. We further investigated whether two molecular species can be discriminated by introducing multiple components into the fitting algorithm. This was simulated by using two molecular classes with different mfps but of equal concentrations and analyzing the composite system using a two-component model. For the special case when the concentration of one species was much larger than the other, the effective τ value converges to that of the dominant species.