Testing the adequacy of the MWC mechanism fitted to ELIC single-channel data. Scheme 1 was fitted directly to a dataset of four idealized single-channel records obtained at 0.5, 1, 5, and 10 mM propylamine. The results of the fit were used to calculate the probability density functions predicted by the scheme. These are shown as solid lines in the top two rows of plots (the dashed lines are the distributions expected if there were no missed events) for open times (top) and shut times (middle). Superimposing these predicted distributions on the experimental histograms for the same records shows that the best fit of MWC does not adequately describe ELIC single-channel kinetics. The bottom-row plots compare the experimental open–shut time correlations in the records of this set (circles, error bars depicting standard deviation of the mean, and connecting lines) and the MWC scheme predictions of these correlations, calculated from the fitted rate constants (solid lines).