Voltage-Driven DNA Translocations through a Nanopore

TLDR

The study aims to determine the velocity of single‑stranded DNA polymers translocating through an α‑hemolysin nanopore. The authors measured current blockade and dwell‑time distributions of voltage‑driven DNA translocations through a single α‑hemolysin pore. The results show that long polymers translocate at a constant speed, while shorter polymers move faster as length decreases, with a nonlinear field dependence, and the data allow estimation of the effective diffusion coefficient and energy penalty for pore extension.

Abstract

We measure current blockade and time distributions for single-stranded DNA polymers during voltage-driven translocations through a single $\ensuremath{\alpha}$-hemolysin pore. We use these data to determine the velocity of the polymers in the pore. Our measurements imply that, while polymers longer than the pore are translocated at a constant speed, the velocity of shorter polymers increases with decreasing length. This velocity is nonlinear with the applied field. Based on this data, we estimate the effective diffusion coefficient and the energy penalty for extending a molecule into the pore.