A Two-Step Method for smFRET Data Analysis.

We demonstrate a two-step data analysis method to increase the accuracy of single-molecule Förster Resonance Energy Transfer (smFRET) experiments. Most current smFRET studies are at a time resolution on the millisecond level. When the system also contains molecular dynamics on the millisecond level, simulations show that large errors are present (e.g., > 40%) because false state assignment becomes significant during data analysis. We introduce and confirm an additional step after normal smFRET data analysis that is able to reduce the error (e.g., < 10%). The idea is to use Monte Carlo simulation to search ideal smFRET trajectories and compare them to the experimental data. Using a mathematical model, we are able to find the matches between these two sets, and back guess the hidden rate constants in the experimental results.