DNA transport in 20nm nanoslits by AC and DC electrical fields

We investigated the transport of λ-DNA in 20 nm nanoslits under the influence of applied AC and DC fields. At DC fields below 15 kV/m it was found that the addition of 1 kHz AC fields with maximum strengths between 10 and 200 kV/m significantly increased the mobility. At DC fields above 15 kV/m no influence of the AC fields was observed. The observed behavior indicates that steric effects rather than dielectrophoretic effects are responsible for the observed low DNA mobility in 20 nm nanoslits. The observed mobility behaviour can be explained if the DNA moves by biased reptation in the nanoslits