Title

Fluorescence Energy Transfer or FRET (Förster Resonance Energy Transfer)

Description

FRET is a technique that, like BRET, allows studying molecular interactions by measuring the energy transfer between two fluorescent molecules, called energy donor and acceptor. This energy transfer occurs by resonance, without photon emission, when the two molecules are very close to each other, typically at a distance of less than 10 nanometers. This energy transfer results in a reduction in the fluorescence emission of the donor and an increase in the fluorescence of the acceptor.

FRET is used to detect interactions between biomolecules, such as protein-protein interactions or changes in molecular conformation, by providing information on the proximity and dynamics of the molecules in their biological environment.
Variants of FRET have been developed to improve the sensitivity of this technique. On the platform, we use assays based on time-resolved FRET or HTRF (Homogeneous Time-Resolved FRET).

In this approach, the energy donor is a long-lived fluorophore (rare earth cryptate), which allows to delay the detection of the fluorescence of fluorescent molecules until the parasitic fluorescences (background noise) have disappeared. This reduces the background noise and increases the signal-to-noise ratio, allowing more precise measurements of molecular interactions.

Applications

HTRF is applied to the monitoring of many cellular events such as ligand-receptor interactions, the quantification of second messengers (cAMP, IP1, etc.), protein phosphorylation (ERK1/2, etc.), arrestin recruitment or receptor internalization.