Forster resonance energy transfer FRET imaging

Second, we present a Forster resonance energy transfer (FRET) imaging method, which has been used to monitor GPGR-mediated dissociation (activation) and reassociation (deactivation) of heterotrimeric G-protein in single live cells (10, 11). Protein/protein interactions cannot be measured by colocalization of the proteins because the limit of resolution of the light microscope using standard techniques is on the order of hundreds of nanometers, and one cannot be certain that two proteins of interest physically interact even... 

Forster (fluorescence) resonance energy transfer (FRET) is the non-radiative energy transfer mechanism between donor chromophore in its excited electronic state and an acceptor chromophore. FRET is extremely sensitive to small distances as the energy transfer is inversely proportional to the distance between the donor and acceptor chromophore to the sixth power, making it highly suitable for imaging and sensing in biomedical. 

DTPA = diethylentetramine-penta-acetate FRET = Forster resonant energy transfer MRI = magnetic resonance imaging NIR = near infra-red PET = positron emission tomography. 

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