1. Collapse of DNA under alternating electric fields.
- Author
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Chunda Zhou and Riehn, Robert
- Subjects
- *
DNA analysis , *ELECTRIC fields , *MOLECULAR physics , *VIDEO microscopy , *SIGNAL frequency estimation - Abstract
Recent studies have shown that double-stranded DNA can collapse in the presence of a strong electric field. Here we provide an in-depth study of the collapse of DNA under weak confinement in microchannels as a function of buffer strength, driving frequency, applied electric-field strength, and molecule size. We find that the critical electric field at which DNA molecules collapse (tens of kV/m) is strongly dependent on driving frequency (100-800 Hz) and molecular size (20-160 kbp), and weakly dependent on the ionic strength (8-60 mM). We argue that an apparent stretching at very high electric fields is an artifact of the finite frame time of video microscopy. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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