Figure 1.

(A) Schematic illustration of DNA translocation through a solid-state nanopore. An electric potential applied across the pore produces an ionic current. (B) The partitioning of DNA into the pore causes well-defined current reductions with different mean current blockade amplitudes (e.g., 〈i_a〉 and 〈i_b〉). (C) A single level event is characterized by the ratio of the mean currents for the occupied and fully open pore (〈i_a〉/〈i₀〉 and the level residence time (Δt). (D) A histogram illustrating the relative current blockade depth for two species obtained by analyzing the events. (E) Residence time distributions for the two blockade depth populations. The mean residence times are estimated from fits to the distributions.