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Updated: Aug 13, 2026

Combining Single-molecule Manipulation and Imaging for the Study of Protein-DNA Interactions
Published on: August 27, 2014
Simultaneous measurements of the electrophoretic mobility, diffusion coefficient and orientation of dsDNA during
Axel Ekani Nkodo1, Bernard Tinland
1Institut Charles Sadron, Centre National de la Recherche Scientifique, 6 rue Boussingault, F-67083 Strasbourg Cedex, France.
Abstract:
We determined simultaneously the electrophoretic mobility, diffusion coefficient D and molecular orientation during electrophoresis of dsDNAs in polymer solutions ranging from the dilute to the semidilute regime. We established, for the first time, master scaling laws for the diffusion coefficient showing a universal behavior. A model found in the literature designed for the dilute regime allows, surprisingly, to describe the mobility data over the whole range of concentrations studied and at the same time the biased reptation with fluctuations (BRF) failed for the semidilute regime, even when constraint release of the network was taken into account. These quantitative determinations of D are of practical interest to evaluate band broadening during capillary electrophoresis and provide data for stimulating investigation of the physics of DNA electrophoretic motion.
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