Förster Resonance Energy Transfer
FRET http://photobiology.info/PDF/History%20of%20FRET.pdf https://link.springer.com/article/10.1140%2Fepjh%2Fe2013-40007-9
by Dr. B. Wieb VanDerMeer, Department of Physics and Astronomy, Western Kentucky University, Bowling Green, KY 42101-1077, USA.
FRET is Fluorescence with Resonance Energy Transfer, or Fluorescence-detected Resonance Energy Transfer, or Förster Resonance Energy Transfer. It is an absorption of electromagnetic radiation by one molecule, the “donor,” followed by resonance interaction with another molecule, the “acceptor.” As a result, energy is transferred from donor to acceptor. The two molecules can be different or identical. If the two molecules are different, the process is called “hetero-transfer” (illustrated in Figure 1). If the two are identical we speak of “homo-transfer” (illustrated in Figure 2) and the energy can go back and forth for a while or go to yet another molecule until emission or a radiation-less transition takes place. FRET is extremely sensitive to the distance between the interacting molecules and can be used to visualize interactions and to measure distances between 1 and 10 nanometers.
FRET can be observed in different ways. A convenient method in the case of hetero-transfer is to examine the effect of FRET on spectra of donors and acceptors as illustrated in Figure 3.
Contents
Acronym
The most frequently used interpretation of the acronym FRET is “Fluorescence Resonance Energy Transfer,” which is incorrect, because fluorescence is not transferred. Correct readings of FRET are “Fluorescence with Resonance Energy Transfer” (preferred by the present author [1]), or “Fluorescence-detected Resonance Energy Transfer” [2], or “Förster Resonance Energy Transfer “ [3, 4]. The phenomenon itself is Resonance Energy Transfer. RET or Resonance Energy Transfer used to be the most popular acronym [5]. Fluorescence serves to detect RET. Förster is the main force behind FRET.