%0 Journal Article
%T Identification of Intensity Ratio Break Points from Photon Arrival Trajectories in Ratiometric Single Molecule Spectroscopy
%A Dieter Bingemann
%A Rachel M. Allen
%J International Journal of Molecular Sciences
%D 2012
%I MDPI AG
%R 10.3390/ijms13067445
%X We£¿describe a statistical method to analyze dual-channel£¿photon arrival trajectories from single molecule spectroscopy model-free to identify break points in the intensity ratio. Photons are binned with a£¿short bin size to calculate the logarithm of the intensity ratio for each bin.£¿Stochastic photon counting noise leads to a near-normal distribution of this logarithm and the standard student t-test£¿is used to find statistically significant changes in this quantity. In stochastic simulations we determine the significance threshold for the t-test¡¯s p-value at a given level of confidence.We test the method¡¯s sensitivity and accuracy indicating that the analysis£¿reliably locates break points with significant changes in the intensity ratio with little or no error in realistic trajectories with large numbers of small change points, while still identifying£¿a large fraction of the frequent break points with small intensity£¿changes. Based on these results we present an approach to estimate confidence intervals for the identified break point locations£¿and recommend a bin size to choose for the analysis. The method proves powerful£¿and reliable in the analysis of simulated and actual data of single molecule reorientation in a glassy matrix.
%K single molecule spectroscopy
%K ratiometric detection
%K statistical analysis
%K glass dynamics
%U http://www.mdpi.com/1422-0067/13/6/7445