Measurement of the repulsive force between polyelectrolyte molecules in ionic solution: hydration forces between parallel DNA double helices.

@article{Rau1984MeasurementOT,
  title={Measurement of the repulsive force between polyelectrolyte molecules in ionic solution: hydration forces between parallel DNA double helices.},
  author={Donald C. Rau and Barbara I Lee and V. Adrian Parsegian},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={1984},
  volume={81 9},
  pages={2621-5}
}
We have measured the repulsive force between B-form double helices in parallel packed arrays of polymer-condensed DNA in the presence of 0.005-1.0 M ionic solutions. Molecular repulsion is consistently exponential with a 2.5-3.5 A decay distance, when the separation between DNA surfaces is 5-15 A. Only weakly dependent on ionic strength and independent of molecular size, this intermolecular repulsion does not obey the predictions of electrostatic double-layer theory. Rather, it strongly… CONTINUE READING