Collapse of DNA in AC Electric Fields

Chunda Zhou, Walter W. Reisner, Rory J. Staunton, Amir Ashan, Robert H. Austin, and Robert Riehn


We report that double-stranded DNA collapses in the presence of ac electric fields at frequencies of a few hundred Hertz, and does not stretch as commonly assumed. In particular, we show that confinement-stretched DNA can collapse to about one quarter of its equilibrium length. We propose that this effect is based on finite relaxation times of the counterion cloud, and the subsequent partitioning of the molecule into mutually attractive units. We discuss alternative models of those attractive units.


DOI


Journal: Physical Review Letters