Lifetime imaging of FRET between red fluorescent proteins

J Biophotonics. 2010 Dec;3(12):774-83. doi: 10.1002/jbio.201000065. Epub 2010 Oct 5.


Numerous processes in cells can be traced by using fluorescence resonance energy transfer (FRET) between two fluorescent proteins. The novel FRET pair including the red fluorescent protein TagRFP and kindling fluorescent protein KFP for sensing caspase-3 activity is developed. The lifetime mode of FRET measurements with a nonfluorescent protein KFP as an acceptor is used to minimize crosstalk due to its direct excitation. The red fluorescence is characterized by a better penetrability through the tissues and minimizes the cell autofluorescence signal. The effective transfection and expression of the FRET sensor in eukaryotic cells is shown by FLIM. The induction of apoptosis by camptothecine increases the fluorescence lifetime, which means effective cleavage of the FRET sensor by caspase-3. The instruments for detecting whole-body fluorescent lifetime imaging are described. Experiments on animals show distinct fluorescence lifetimes for the red fluorescent proteins possessing similar spectral properties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Apoptosis / drug effects
  • Camptothecin / pharmacology
  • Caspase 3 / metabolism
  • Eukaryotic Cells / metabolism
  • Eukaryotic Cells / pathology*
  • Eukaryotic Cells / ultrastructure
  • Fluorescence Resonance Energy Transfer / methods*
  • Luminescent Agents*
  • Luminescent Proteins*
  • Mice
  • Mice, Nude
  • Red Fluorescent Protein
  • Whole Body Imaging / methods*


  • Antineoplastic Agents, Phytogenic
  • Luminescent Agents
  • Luminescent Proteins
  • Caspase 3
  • Camptothecin