Förster Resonance Energy Transfer (FRET)

Fluorescence or Förster resonance energy transfer (FRET) is a distance-dependent transfer of energy between two chromophores, a donor and an acceptor. When in close physical proximity, a donor chromophore in its electronic excited state transfer energy to an acceptor chromophore. This non-radiative transfer of energy is accomplished through long-range dipole-dipole coupling interactions between the donor and acceptor chromophores. As a result, the transfer of energy quenches the fluorescence intensity of the donor, reduces its excited state lifetime. FRET donor must be strongly fluorescent to have an efficient FRET process. However, FRET acceptors can be either fluorescent or non-fluorescent (dark FRET). For the dark FRET, acceptors are generally referred as quenchers. Tide Quencher™ dyes are by far the most efficient and complete family of quenchers that are widely used for preparing peptides and oligonucleotides that are used in a variety of biological detections.