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L. Schrangl, J. Göhring, G. Schütz:
"Kinetic analysis of single molecule FRET transitions without trajectories";
Journal of Chemical Physics, 148 (2018), 1233281 - 1233289.

Single molecule F¨orster resonance energy transfer (smFRET) is a popular tool to study biological
systems that undergo topological transitions on the nanometer scale. smFRET experiments typically
require recording of long smFRET trajectories and subsequent statistical analysis to extract parameters
such as the states´ lifetimes. Alternatively, analysis of probability distributions exploits the shapes
of smFRET distributions at well chosen exposure times and hence works without the acquisition
of time traces. Here, we describe a variant that utilizes statistical tests to compare experimental
datasets with Monte Carlo simulations. For a given model, parameters are varied to cover the full
realistic parameter space. As output, the method yields p-values which quantify the likelihood for each
parameter setting to be consistent with the experimental data. The method provides suitable results
even if the actual lifetimes differ by an order of magnitude.We also demonstrated the robustness of the
method to inaccurately determine input parameters. As proof of concept, the new method was applied
to the determination of transition rate constants for Holliday junctions.