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Coil-globule transition of DNA molecules induced by cationic surfactants: A dynamic light scattering study

Dias, Rita LU ; Innerlohinger, J; Glatter, O; Miguel, Maria LU and Lindman, Björn LU (2005) In The Journal of Physical Chemistry Part B 109(20). p.10458-10463
Abstract
The compaction and aggregation of DNA induced by cationic surfactants was studied by dynamic light scattering (DLS). Furthermore, the effect on surfactant-compacted DNA of the addition of nonionic amphiphiles and salt was studied. When using sufficiently low amounts of DNA and cetyltrimethylammonium bromide (CTAB), compacted DNA molecules could be monitored by the appearance of a band characterized by lower hydrodynamic radius and by the decrease in the intensity of the peak corresponding to extended DNA molecules. Notably, we observed a region where compacted molecules coexist with extended ones; these two populations were found to be stable with time. For higher concentrations of CTAB, only compacted molecules were observed and the size... (More)
The compaction and aggregation of DNA induced by cationic surfactants was studied by dynamic light scattering (DLS). Furthermore, the effect on surfactant-compacted DNA of the addition of nonionic amphiphiles and salt was studied. When using sufficiently low amounts of DNA and cetyltrimethylammonium bromide (CTAB), compacted DNA molecules could be monitored by the appearance of a band characterized by lower hydrodynamic radius and by the decrease in the intensity of the peak corresponding to extended DNA molecules. Notably, we observed a region where compacted molecules coexist with extended ones; these two populations were found to be stable with time. For higher concentrations of CTAB, only compacted molecules were observed and the size of the particles increased with time indicating aggregation. The number of globules present in the coexistence region increased linearly with the surfactant concentrations, as given by the area of the band corresponding to this population, which indicates a double-cooperativity of the binding. The DLS experiments were in good agreement with previous fluorescence microscopy studies, with certain advantages over this technique since there is no need to add fluorescence dyes and antioxidants. Furthermore, it allows the study of molecules which are too small to be visualized by fluorescence microscopy. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
The Journal of Physical Chemistry Part B
volume
109
issue
20
pages
10458 - 10463
publisher
The American Chemical Society
external identifiers
  • wos:000229296600078
  • scopus:20344406486
ISSN
1520-5207
DOI
10.1021/jp0444464
language
English
LU publication?
yes
id
926f6b7f-eba1-4098-a1eb-ddc9ea186bd8 (old id 157318)
date added to LUP
2007-07-11 09:57:36
date last changed
2017-09-03 04:40:06
@article{926f6b7f-eba1-4098-a1eb-ddc9ea186bd8,
  abstract     = {The compaction and aggregation of DNA induced by cationic surfactants was studied by dynamic light scattering (DLS). Furthermore, the effect on surfactant-compacted DNA of the addition of nonionic amphiphiles and salt was studied. When using sufficiently low amounts of DNA and cetyltrimethylammonium bromide (CTAB), compacted DNA molecules could be monitored by the appearance of a band characterized by lower hydrodynamic radius and by the decrease in the intensity of the peak corresponding to extended DNA molecules. Notably, we observed a region where compacted molecules coexist with extended ones; these two populations were found to be stable with time. For higher concentrations of CTAB, only compacted molecules were observed and the size of the particles increased with time indicating aggregation. The number of globules present in the coexistence region increased linearly with the surfactant concentrations, as given by the area of the band corresponding to this population, which indicates a double-cooperativity of the binding. The DLS experiments were in good agreement with previous fluorescence microscopy studies, with certain advantages over this technique since there is no need to add fluorescence dyes and antioxidants. Furthermore, it allows the study of molecules which are too small to be visualized by fluorescence microscopy.},
  author       = {Dias, Rita and Innerlohinger, J and Glatter, O and Miguel, Maria and Lindman, Björn},
  issn         = {1520-5207},
  language     = {eng},
  number       = {20},
  pages        = {10458--10463},
  publisher    = {The American Chemical Society},
  series       = {The Journal of Physical Chemistry Part B},
  title        = {Coil-globule transition of DNA molecules induced by cationic surfactants: A dynamic light scattering study},
  url          = {http://dx.doi.org/10.1021/jp0444464},
  volume       = {109},
  year         = {2005},
}