title: Continuity of states between the cholesteric → line hexatic transition and the condensation transition in DNA solutions.
abstract: A new method of finely temperature-tuning osmotic pressure allows one to identify the cholesteric → line hexatic transition of oriented or unoriented long-fragment DNA bundles in monovalent salt solutions as first order, with a small but finite volume discontinuity. This transition is similar to the osmotic pressure-induced expanded → condensed DNA transition in polyvalent salt solutions at small enough polyvalent salt concentrations. Therefore there exists a continuity of states between the two. This finding, together with the corresponding empirical equation of state, effectively relates the phase diagram of DNA solutions for monovalent salts to that for polyvalent salts and sheds some light on the complicated interactions between DNA molecules at high densities.
authors.affiliation: Department of Physics, University of Massachusetts, Amherst, MA 01003, United States.
authors.forename: Selcuk
authors.initials: S
authors.lastname: Yasar
authors.affiliation: 1] Department of Physics, University of Massachusetts, Amherst, MA 01003, United States [2] Department of Theoretical Physics, J. Stefan Institute, SI-1000 Ljubljana, Slovenia [3] Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Podgornik
authors.affiliation: 1] Institut Laue Langevin, BP 156, 6, rue Jules Horowitz 38042 Grenoble Cedex 9, France [2] Laboratoire de Physique, Ecole Normale Superiéure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France.
authors.forename: Jessica
authors.initials: J
authors.lastname: Valle-Orero
authors.affiliation: Institut Laue-Langevin, 6 rue Jules Horowitz, BP156 38042, Grenoble, France.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Johnson
authors.affiliation: Department of Physics, University of Massachusetts, Amherst, MA 01003, United States.
authors.forename: V Adrian
authors.initials: VA
authors.lastname: Parsegian
mesh_terms: D004247:DNA / Q000737:chemistry*; D050866:Liquid Crystals / Q000737:chemistry; D009690:Nucleic Acid Conformation; D009997:Osmotic Pressure; D012965:Sodium Chloride / Q000737:chemistry; D012996:Solutions; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D012996:Solutions; D012965:Sodium Chloride; D004247:DNA