Photobleaching and sensitized emission-based methods for the detection of förster resonance energy transfer

Abstract

Förster resonance energy transfer (FRET) is a non-radiative interaction between two molecules that happens at distances in the range of a few nanometers. Using FRET interactions between suitably selected fluorophores allows to study molecular interactions or conformational changes of single molecules on fluorescence microscopes even though the optical resolution of the microscope is limited to distances that are almost two orders of magnitude higher. In this chapter several variants of FRET detection methods are described that are based either on the targeted photobleaching of one of the participating molecule species or on the direct detection of the fluorescence signal that is created as a result of the FRET interactions.