Osmotic properties of DNA: Critical evaluation of counterion condensation theory
Abstract
The osmotic coefficient of B-DNA in water may, in dilute solutions, deviate by as much as 100% from predictions based on a simple line-charge ``counterion condensation'' theory. In contrast, a cell model description of the ionic atmosphere near a cylindrical polyelectrolyte predicts osmotic properties that are in surprisingly good harmony with all available experimental findings over a wide range of DNA concentrations. We argue that the neglect of molecular features, such as finite radius, makes line-charge condensation theory inapplicable at all but impractically low polyelectrolyte concentrations.
- Publication:
-
Physical Review E
- Pub Date:
- August 2001
- DOI:
- 10.1103/PhysRevE.64.021907
- Bibcode:
- 2001PhRvE..64b1907H
- Keywords:
-
- 87.15.Nn;
- 61.30.-v;
- 64.30.+t;
- 87.14.Gg;
- Properties of solutions;
- aggregation and crystallization of macromolecules;
- Liquid crystals;
- Equations of state of specific substances;
- DNA RNA