Förster Resonance Energy Transfer (FRET) is a process where an excited
fluorophore (donor)transfers energy to another fluorophore (acceptor). Resonance energy transfer is a distance-dependent phenomenon due to
the dipole-dipole interaction between the donor and acceptormolecules.
efficiency of the energy transfer is sensitive to the molecular
distances andnegligible at distances longer than 10nm for the common
fluorophores used in biologicalapplications. For this reason, when FRET
is combined with fluorescence microscopy in biologicalsamples, it can be
used to report molecular associations and biochemical reactions
allowing themto be located precisely at the subcellular level where
these processes are taking place.