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Coil-stretch Transition of DNA Molecules in Slit-like Confinement.

ABSTRACT: We experimentally investigate the influence of slit-like confinement on the coil-stretch transition of single DNA molecules in a homogeneous planar elongational electric field. We observe a more gradual coil-stretch transition characterized by two distinct critical strain rates for DNA in confinement, different from the unconfined case where a single critical strain rate exists. We postulate that the change in the coil-stretch transition is due to a modified spring law in confinement. We develop a dumbbell model to extract an effective spring law by following the relaxation of an initially stretched DNA. We then use this spring law and kinetic theory modeling to predict the extension and fluctuations of DNA in planar elongational fields. The model predicts that a two-stage coil-stretch transition emerges in confinement, in accord with experimental observations.

SUBMITTER: Tang J

PROVIDER: S-EPMC3050490 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature

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Coil-stretch Transition of DNA Molecules in Slit-like Confinement.

Tang Jing J Trahan Daniel W DW Doyle Patrick S PS

Macromolecules 20100301 6

We experimentally investigate the influence of slit-like confinement on the coil-stretch transition of single DNA molecules in a homogeneous planar elongational electric field. We observe a more gradual coil-stretch transition characterized by two distinct critical strain rates for DNA in confinement, different from the unconfined case where a single critical strain rate exists. We postulate that the change in the coil-stretch transition is due to a modified spring law in confinement. We develop ...[more]

PMID: 21399708

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