Lose Control my Friend

My fault, my failure, is not in the passions I have, but in my lack of control of them.

- Jack Kerouac (Novelist)

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Don't Fret the Small Stuff - Harmony is Within Your Grasp - Another planksip® Möbius

Förster resonance energy transfer is another (FRET)

Förster resonance energy transfer (FRET), fluorescence resonance energy transfer (FRET), resonance energy transfer (RET) or electronic energy transfer (EET) is a mechanism describing energy transfer between two light-sensitive molecules (chromophores).[1] A donor chromophore, initially in its electronic excited state, may transfer energy to an acceptor chromophore through nonradiative dipole–dipole coupling.[2] The efficiency of this energy transfer is inversely proportional to the sixth power of the distance between donor and acceptor, making FRET extremely sensitive to small changes in distance.[3]

Measurements of FRET efficiency can be used to determine if two fluorophores are within a certain distance of each other.[4] Such measurements are used as a research tool in fields including biology and chemistry.

FRET is analogous to near-field communication, in that the radius of interaction is much smaller than the wavelength of light emitted. In the near-field region, the excited chromophore emits a virtual photon that is instantly absorbed by a receiving chromophore. These virtual photons are undetectable, since their existence violates the conservation of energy and momentum, and hence FRET is known as a radiationless mechanism. Quantum electrodynamical calculations have been used to determine that radiationless (FRET) and radiative energy transfer are the short- and long-range asymptotes of a single unified mechanism.[5]-[6]


  1. Cheng, Ping-Chin (2006). "The Contrast Formation in Optical Microscopy". In Pawley, James B. Handbook Of Biological Confocal Microscopy (3rd ed.). New York, NY: Springer. pp. 162–206. doi:10.1007/978-0-387-45524-2_8. ISBN 978-0-387-25921-5. ↩︎

  2. Helms, Volkhard (2008). "Fluorescence Resonance Energy Transfer". Principles of Computational Cell Biology. Weinheim: Wiley-VCH. p. 202. ISBN 978-3-527-31555-0. ↩︎

  3. Harris, Daniel C. (2010). "Applications of Spectrophotometry". Quantitative Chemical Analysis (8th ed.). New York: W. H. Freeman and Co. pp. 419–44. ISBN 978-1-4292-1815-3. ↩︎

  4. Zheng, Jie (2006). "Spectroscopy-Based Quantitative Fluorescence Resonance Energy Transfer Analysis". In Stockand, James D.; Shapiro, Mark S. Ion Channels: Methods and Protocols. Methods in Molecular Biology, Volume 337. Totowa, NJ: Humana Press. pp. 65–77. doi:10.1385/1-59745-095-2:65. ISBN 978-1-59745-095-9. ↩︎

  5. Andrews, David L. (1989). "A unified theory of radiative and radiationless molecular energy transfer". Chemical Physics. 135 (2): 195–201. Bibcode:1989CP....135..195A. doi:10.1016/0301-0104(89)87019-3 ↩︎

  6. Andrews, David L; Bradshaw, David S (2004). "Virtual photons, dipole fields and energy transfer: A quantum electrodynamical approach". European Journal of Physics. 25 (6): 845–858. doi:10.1088/0143-0807/25/6/017 ↩︎