Albany 2013: Book of Abstracts
June 11-15 2013
©Adenine Press (2012)
Electrophoresis and Capture of DNA into a Nanopore
DNA capture into a nanopore is driven by the electric field which extends out of the pore and is not subject to Debye screening, because it is maintained by the externally applied voltage (M.Wanunu et al, 2010). This outside field is closely related to the pore access resistance (Kowalczyk et al, 2011). DNA motion in this highly non-uniform field is coupled to both electric and hydrodynamic currents. To understand this complex dynamics, we develop a set of scaling arguments. First we re-examine the classical problem of DNA electrophoresis in a uniform field and re-derive the known results for DNA electrophoretic mobility which does not depend on DNA length. Second, we generalize these scaling arguments for the non-uniform field. We show that the distance between DNA end and the pore entrance can be viewed as a reaction coordinate describing the capture process, and this description remains marginally applicable up until DNA entrance into the pore. This description naturally couples to the non-equilibrium description of DNA translocation based on the concept of iso-flux trumpet (Rowghanian & Grosberg, 2011).
This research was sponsored in part by the US-Israel Binational Science Foundation.
P. Rowghanian, & A. Y. Grosberg (2011). Force driven polymer translocation through a nanopore: an old problem revisited. Journal of Physical Chemistry B, 115, 14127-14135.
M. Wanunu, W. Morrison, Y. Rabin, A. Y. Grosberg, & A. Meller (2010) Electrostatic focusing of unlabeled DNA into nanoscale pores using a salt gradient. Nature Nanotechnology 5, 160-165.
Department of Physics and Center for Soft Matter research