Fluorescence anisotropy

Time-resolved fluorescence anisotropy is used to obtain information about molecular rotation and homo-FRET between proteins.

The rotational dynamics are determined by e.g. the shape of the protein and its aggregation state, or the viscosity of the medium surrounding the fluorescent molecule.
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Rotations and/or energy transfer typically take place on a timescale similar to fluorescence. So, by measuring the fluorescence anisotropy with time resolved fluorescence it is possible to determine rotational correlation times and homo-FRET efficiencies. Our time-correlated single photon counting (TCSPC) set-up is equipped with polarization optics to enable time resolved fluorescence anisotropy experiments.