Fluorescence lifetime is a measure of the time (picoseconds to 100s nanoseconds) a fluorophore spends in the excited state before returning to the ground state
Fluorescence lifetimes varies according to the environment: the medium, pH, temperature, viscosity, proximity to an acceptor (FRET)…
Fluoresecence lifetime microscopy enables to measure FRET between a donor (GFP) and an acceptor (mCherry) associated to proteins of interest.
At the BIC, we have two systems to measure the fluorescence lifetime:
1) Time-domain based on an inverted scanning confocal microscope
2) Frequency-domain installed on a widefield microscope
Contact: Christel Poujol
FLIM image of a double transfected neurons displaying the molecular interaction between PSD-95 proteins and Stargazin at the synapses. The colored code represents the lifetime. The shorter lifetime indicate the FRET signal. Anne-Sophie Hafner, Pato Opazo, IINS UMR 5297 CNRS