title: Purification of A-form DNA fiber samples by the removal of B-form DNA residues.
abstract: To date, fiber diffraction on A-form NaDNA has always shown a B-form contamination. Here we have used optic microscopy, calorimetry, and neutron scattering techniques to define a method to obtain DNA fibres samples whose molecules are purely in the A-form. When the impure sample is heated to 320 K, the DNA molecules in the B-form undergo a transition into the A-form. Our studies have modified the accepted phase diagram for NaDNA films by including the dependence of temperature crucial for the purification of A-form samples by removal of B-form contamination.
authors: Institut Laue Langevin, BP 156, 6, rue Jules Horowitz 38042 Grenoble Cedex 9, France. valleorero@ill.fr
authors: Jessica
authors: J
authors: Valle-Orero
authors: Andrew
authors: A
authors: Wildes
authors: Jean-Luc
authors: JL
authors: Garden
authors: Michel
authors: M
authors: Peyrard
mesh_terms: D002152:Calorimetry, Differential Scanning; D044704:DNA, A-Form / Q000737:chemistry / Q000302:isolation & purification*; D059371:DNA, B-Form / Q000737:chemistry / Q000302:isolation & purification*; D033363:Neutron Diffraction; D009690:Nucleic Acid Conformation; D044367:Phase Transition; D053838:Scattering, Small Angle; D013696:Temperature
chemical_list: D044704:DNA, A-Form; D059371:DNA, B-Form