Fluorescence resonance energy transfer imaging as a tool for in situ evaluation of cell morphofunctional characteristics

Two fluorochromes can give rise to an energy transfer process provided that they meet the required spectral conditions and spatial relationships. In particular, according to Foerster's theory, the efficiency of the energy transfer process depends on (i) the overlapping of the fluorescence spectrum of the fluorochrome considered as the donor with the absorption spectrum of the fluorochrome acting as the acceptor, and (ii) the distance and reciprocal orientation of the molecules of the two fluorochromes. Thus, fluorescence resonance energy transfer can be employed as a tool for the spectroscopic study of the spatial relationships in the supramolecular arrangement of biological macromolecules, and therefore of the related functional properties.