Glassy behavior of denatured DNA films studied by Differential Scanning Calorimetry

Jessica Valle Orero (1, 2) , Jean-Luc Garden (3) , Jacques Richard (4) , Andrew Wildes (1) , Michel Peyrard (2)

1 ILL - Institut Laue-Langevin
2 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
3 NEEL - ThEMA - Thermique Elaboration Matériaux Applications
4 NEEL - TPS - Thermodynamique et biophysique des petits systèmes

We use differential scanning calorimetry (DSC) to study the properties of DNA films, made of oriented fibers, heated above the thermal denaturation temperature of the double helical form. The films show glassy properties that we investigate in two series of experiments, a slow cooling at different rates followed by a DSC scan upon heating, and aging at a temperature below the glass transition. Introducing the fictive temperature to characterize the glass allows us to derive quantitative information on the relaxations of the DNA films, in particular to evaluate their enthalpy barrier. A comparison with similar aging studies on PVAc highlights some specificities of the DNA samples.

Keywords: Glass transition; biopolymer; DNA fibers; PVAc; fictive temperature; DSC; aging

Domains: Physics [physics]; Condensed Matter [cond-mat]; Statistical Mechanics [cond-mat.stat-mech]

Jessica Valle Orero, Jean-Luc Garden, Jacques Richard, Andrew Wildes, Michel Peyrard. Glassy behavior of denatured DNA films studied by Differential Scanning Calorimetry. Journal of Physical Chemistry B, 2012, 116, pp.4394-4402. ⟨10.1021/jp301128j⟩. ⟨ensl-00690342⟩