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Compression and self-entanglement of single DNA molecules under uniform electric field.

ABSTRACT: We experimentally study the effects of a uniform electric field on the conformation of single DNA molecules. We demonstrate that a moderate electric field (~200 V/cm) strongly compresses isolated DNA polymer coils into isotropic globules. Insight into the nature of these compressed states is gained by following the expansion of the molecules back to equilibrium after halting the electric field. We observe two distinct types of expansion modes: a continuous molecular expansion analogous to a compressed spring expanding, and a much slower expansion characterized by two long-lived metastable states. Fluorescence microscopy and stretching experiments reveal that the metastable states are the result of intramolecular self-entanglements induced by the electric field. These results have broad importance in DNA separations and single molecule genomics, polymer rheology, and DNA-based nanofabrication.

SUBMITTER: Tang J

PROVIDER: S-EPMC3182689 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature

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Compression and self-entanglement of single DNA molecules under uniform electric field.

Tang Jing J Du Ning N Doyle Patrick S PS

Proceedings of the National Academy of Sciences of the United States of America 20110912 39

We experimentally study the effects of a uniform electric field on the conformation of single DNA molecules. We demonstrate that a moderate electric field (~200 V/cm) strongly compresses isolated DNA polymer coils into isotropic globules. Insight into the nature of these compressed states is gained by following the expansion of the molecules back to equilibrium after halting the electric field. We observe two distinct types of expansion modes: a continuous molecular expansion analogous to a comp ...[more]

PMID: 21911402

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Dataset Information

Compression and self-entanglement of single DNA molecules under uniform electric field.

Publications

Compression and self-entanglement of single DNA molecules under uniform electric field.

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