FRET or no FRET: a quantitative comparison.
Fluorescence resonance energy transfer (FRET) is a technique used to measure the interaction between two molecules labeled with two different fluorophores (the donor and the acceptor) by the transfer of energy from the excited donor to the acceptor. In biological applications, this technique has become popular to qualitatively map protein-protein interactions, and in biophysical projects it is used as a quantitative measure for distances between a single donor and acceptor molecule. Numerous approaches can be found in the literature to quantify and map FRET, but the measures they provide are often difficult to interpret. We propose here a quantitative comparison of these methods by using a surface FRET system with controlled amounts of donor and acceptor fluorophores and controlled distances between them. We support the system with a Monte Carlo simulation of FRET, which provides reference values for the FRET efficiency under various experimental conditions. We validate a representative set of FRET efficiencies and indices calculated from the different methods with different experimental settings. Finally, we test their sensitivity and draw conclusions for the preparation of FRET experiments in more complex and less-controlled systems.
Berney
Claude
C
BioMicroMetrics Group, Laboratory for Biomechanics, Swiss Federal Institute of Technology, CH-8952 Schlieren, Switzerland. berney@biomech.mavt.ethz.ch
Danuser
Gaudenz
G
D000465:Algorithms; D016477:Artifacts; D001710:Biotin / Q000737:chemistry* / Q000592:standards; D031541:Fluorescence Resonance Energy Transfer / Q000295:instrumentation / Q000379:methods* / Q000592:standards*; D005456:Fluorescent Dyes; D009010:Monte Carlo Method; D011485:Protein Binding; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019809:Streptavidin / Q000737:chemistry* / Q000592:standards
D005456:Fluorescent Dyes; D001710:Biotin; D019809:Streptavidin