FörsterResonanzEnergieübertragungseffekt

Förster Resonance Energy Transfer, often abbreviated as FRET, is a non-radiative energy transfer mechanism that occurs between two light-sensitive molecules called chromophores. It is a distance-dependent process where energy is transferred from an excited donor fluorophore to an acceptor molecule. For FRET to occur, the emission spectrum of the donor must overlap with the absorption spectrum of the acceptor, and the donor and acceptor must be in close proximity, typically within 10 nanometers. The efficiency of energy transfer is highly sensitive to the distance between the donor and acceptor, decreasing with the sixth power of the separation distance. This distance dependence makes FRET a powerful tool for measuring molecular interactions and conformational changes in biological systems.

FRET is widely used in various scientific disciplines, including biochemistry, biophysics, and cell biology. It can be employed to study protein-protein interactions, DNA hybridization, and conformational dynamics of biomolecules. By attaching fluorescent labels to molecules of interest, researchers can detect whether they are interacting or changing shape based on the FRET signal. For instance, if two proteins interact, and one is labeled with a donor fluorophore and the other with an acceptor, FRET will be observed. Conversely, if they are not interacting, or if their conformation changes such that they move apart, the FRET signal will diminish. This sensitivity to distance and interaction has made FRET an indispensable technique for probing molecular events in real-time and in situ.