Förster Resonance Energy Transfer (FRET)
Forster Resonance Energy Transfer occurs between two appropriately positioned fluorophores only when the distance separating them is less than 10 nanometers. Thus, this technique is often used in single molecule assays as well as in intact cells and whole organisms to determine the spatial proximity of molecules.
Basics of FRET Microscopy
Using fluorescence to examine dynamic interactions between probes in living cells.