Understanding ion currents in DNA translocation experiments

by Stefan Kesselheim (Institute for Computational Physics University of Stuttgart, Germany)

Friday 19 Oct 2012, 11:00 → 13:00 Europe/Rome

Aula Corbino (Dip. di Fisica - Edificio E. Fermi)

We investigate ion currents in DNA translocation experiments by means of continuum modelling, coarse grained hybrid Molecular Dynamics/Lattice Boltzmann simulations and, atomistic simulations. The ion current is the key observable in these experiments, where single DNA molecules are dragged through nanometer-sized pores in membranes, that might even allow to construct DNA sequencing devices based on nanopores. The current modulation caused by the DNA can be decomposed into three physical effects: the exclusion of ions from the DNAs volume; the attraction of counterions; and friction between DNA and ions. We compare the quantitative influence of all three contributions, using models of different resolution, finding, finally, that atomistic simulations provide good agreement with experiments.