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Nanoconfinement-enhanced conformational response of single DNA molecules to changes in ionic environment

Reisner, Walter; Beech, Jason LU ; Larsen, Niels B.; Flyvbjerg, Henrik; Kristensen, Anders and Tegenfeldt, Jonas LU (2007) In Physical Review Letters 99(5).
Abstract
We show that the ionic environment plays a critical role in determining the configurational properties of DNA confined in silica nanochannels. The extension of DNA in the nanochannels increases as the ionic strength is reduced, almost tripling over two decades in ionic strength for channels around 100x100 nm in dimension. Surprisingly, we find that the variation of the persistence length alone with ionic strength is not enough to explain our results. The effect is due mainly to increasing self-avoidance created by the reduced screening of electrostatic interactions at low ionic strength. To quantify the increase in self-avoidance, we introduce a new parameter into the de Gennes theory: an effective DNA width that gives the increase in the... (More)
We show that the ionic environment plays a critical role in determining the configurational properties of DNA confined in silica nanochannels. The extension of DNA in the nanochannels increases as the ionic strength is reduced, almost tripling over two decades in ionic strength for channels around 100x100 nm in dimension. Surprisingly, we find that the variation of the persistence length alone with ionic strength is not enough to explain our results. The effect is due mainly to increasing self-avoidance created by the reduced screening of electrostatic interactions at low ionic strength. To quantify the increase in self-avoidance, we introduce a new parameter into the de Gennes theory: an effective DNA width that gives the increase in the excluded volume due to electrostatic repulsion. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review Letters
volume
99
issue
5
publisher
American Physical Society
external identifiers
  • wos:000248597500069
  • scopus:34547690725
ISSN
1079-7114
DOI
10.1103/PhysRevLett.99.058302
language
English
LU publication?
yes
id
aebed029-b6c2-4759-a861-64df90d926d0 (old id 690773)
date added to LUP
2007-12-20 08:52:20
date last changed
2017-09-10 03:42:48
@article{aebed029-b6c2-4759-a861-64df90d926d0,
  abstract     = {We show that the ionic environment plays a critical role in determining the configurational properties of DNA confined in silica nanochannels. The extension of DNA in the nanochannels increases as the ionic strength is reduced, almost tripling over two decades in ionic strength for channels around 100x100 nm in dimension. Surprisingly, we find that the variation of the persistence length alone with ionic strength is not enough to explain our results. The effect is due mainly to increasing self-avoidance created by the reduced screening of electrostatic interactions at low ionic strength. To quantify the increase in self-avoidance, we introduce a new parameter into the de Gennes theory: an effective DNA width that gives the increase in the excluded volume due to electrostatic repulsion.},
  articleno    = {058302},
  author       = {Reisner, Walter and Beech, Jason and Larsen, Niels B. and Flyvbjerg, Henrik and Kristensen, Anders and Tegenfeldt, Jonas},
  issn         = {1079-7114},
  language     = {eng},
  number       = {5},
  publisher    = {American Physical Society},
  series       = {Physical Review Letters},
  title        = {Nanoconfinement-enhanced conformational response of single DNA molecules to changes in ionic environment},
  url          = {http://dx.doi.org/10.1103/PhysRevLett.99.058302},
  volume       = {99},
  year         = {2007},
}