Energy Transfer Systems for In Vivo Tracking.

With recent advances, fluorescent imaging has gained momentum as an important tool for in vivo imaging. FRET systems consist of molecules that absorb in the near-infrared region which are efficient candidates for in vivo imaging, basic research, and clinical applications. Nontoxic, photostable fluorophores, such as fluorescent proteins and dyes, can successfully be used to visualize spatial and temporal dynamics of living cells. Selected cells to be injected are first tagged with the FRET-based biosensor and then injected to the living animal. Then, these foreign cells in the host body can be visualized under fluorescence microscope via excitation of the fluorophores at the correct wavelength.