title: Viscosity measurements of DNA solutions with and without condensing agents.
abstract: Aqueous solutions calf thymus DNA at three concentrations were studied by viscosity measurements at ambient pressure. A gravitational capillary viscometer and a rotating cylinder viscometer were employed. Three polycations were tested as viscosity-reducing agents with measurements from 25°C to 50°C. The most significant viscosity reduction was achieved with spermine in a solution of DNA at 2 mg/ml concentration. Measurements of DNA solutions without agents from 10°C to 90°C revealed concentration-dependent viscosity maxima in the range from 50°C to 65°C. The associated increases in viscosity were as high as 400%. A two-liquids model for solutions of double- and single-stranded DNA was developed that closely represented the experimental data.
authors.affiliation: National Institute of Standards and Technology, Material Measurement Laboratory, Applied Chemicals and Materials Division, Boulder, CO, USA.
authors.forename: Arno
authors.initials: A
authors.lastname: Laesecke
authors.affiliation: National Institute of Standards and Technology, Material Measurement Laboratory, Applied Chemicals and Materials Division, Boulder, CO, USA.
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Burger
mesh_terms: D000818:Animals; D001809:Blood Viscosity / Q000502:physiology*; D002417:Cattle; D003550:Cystic Fibrosis / Q000097:blood*; D004247:DNA / Q000097:blood*
chemical_list: D004247:DNA; C427203:calf thymus DNA
keywords: Calf thymus DNA; capillary viscometer; cystic fibrosis; rotating concentric cylinder viscometer; sputum; viscosity