Figure 1.

A cartoon figure illustrating smFRET data. For the experiments considered here, the kinetics along the reaction coordinate defined along the donor-acceptor distance are monitored using single-photon arrival data. In the figure above, photon arrivals are represented by green dots for photons arriving into the donor channel and red dots for photons arriving in the acceptor channel. For the case where donor and acceptor label one molecule, a molecule’s transitions between system states (coinciding with conformations) is reflected by the distance between labels measured by variations in detected photon arrival times and colors.