Overview of interaction and photophysical model. (A) In the underlying interaction, a donor-tagged protein binds an acceptor-tagged protein with dissociation constant Kd. (B) During a FRET experiment, photophysical events occur such as FRET, which occurs between donors and acceptors in complex with efficiency Efr, and the excitation of and emissions from donors and acceptors, where the factor relating fluorescence observed in channel i to the concentration of species S is . We include all possible spectral overlap effects, allowing the donor and acceptor to be excited and emit photons in all spectral channels.
Lichten and Swain BMC Biophysics 2011 4:10 doi:10.1186/2046-1682-4-10