Figure 5

Panel (A) shows a 100 ms blockade trace with one blockade "spike" event, and the signal analysis that results from analysis of hundred of seconds of blockade data from the same species of molecule. The molecule studied in (A) is 9 base-pair hairpin that is the radiation damaged DNA model (a terminal guanine is oxolated) of the molecule studied in (B), with terminal guanine unaltered in the "non-radiated" molecule. The spike count plots show increasing counts as spike cut-off thresholds are relaxed (to where eventually any downward deflection will be counted as a spike). Plots are automatically generated using gnuplot and automatically fit with extrapolations of their linear phases at the group's tools website. The extrapolations provide an estimate of "true" anomalous spike counts – counts associated with terminus fraying in the captured DNA hairpin (as shown in [44]). The radiated form of the molecule frayed 17.6 times on average (while in the LL state), while the non-radiated molecule only frayed 3.58 times a second, on average.