Abstract
DNA and RNA molecules can be electrophoreticaly threaded through
nanoscale pores, such as the ∼1.5 nm alpha-Hemolysin. Information
about their translocation dynamics is obtained by probing the ionic
current flowing through the pore during their passage. We experimentally
study the translocation process of unstructured and structured DNA
molecules through a single nanopore. We find that the translocation
process depends on DNA properties, such as its sequence and its
direction of entry. With intense electrical field structured DNA and RNA
can be unzipped in a controlled way, and the unzipping kinetics can be
directly quantified. We study the unzipping kinetics of DNA and RNA
molecules under a wide range of voltage gradients. We find that the
unzipping kinetics is characterized by two limiting regimes: the strong
field limit in which the system is unzipped in an irreversible process,
and the weak field regime, in which it is in quasi equilibrium.
Interestingly the unzipping kinetics of RNA molecules is very different
from their DNA analogues. A theoretical model that accounts for our
experimental results will be discussed.
Original language | English |
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Title of host publication | American Physical Society, APS March Meeting, March 13-17, 2006 |
State | Published - Mar 2006 |