title: Measuring inter-DNA potentials in solution.
abstract: Interactions between short strands of DNA can be tuned from repulsive to attractive by varying solution conditions and have been quantified using small angle x-ray scattering techniques. The effective DNA interaction charge was extracted by fitting the scattering profiles with the generalized one-component method and inter-DNA Yukawa pair potentials. A significant charge is measured at low to moderate monovalent counterion concentrations, resulting in strong inter-DNA repulsion. The charge and repulsion diminish rapidly upon the addition of divalent counterions. An intriguing short range attraction is observed at surprisingly low divalent cation concentrations, approximately 16 mM Mg2+. Quantitative measurements of inter-DNA potentials are essential for improving models of fundamental interactions in biological systems.
authors.affiliation: School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Xiangyun
authors.initials: X
authors.lastname: Qiu
authors.forename: Lisa W
authors.initials: LW
authors.lastname: Kwok
authors.forename: Hye Yoon
authors.initials: HY
authors.lastname: Park
authors.forename: Jessica S
authors.initials: JS
authors.lastname: Lamb
authors.forename: Kurt
authors.initials: K
authors.lastname: Andresen
authors.forename: Lois
authors.initials: L
authors.lastname: Pollack
mesh_terms: D004277:DNA, Single-Stranded / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D008958:Models, Molecular; D009010:Monte Carlo Method; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D012996:Solutions / Q000737:chemistry; D055672:Static Electricity; D014961:X-Ray Diffraction
chemical_list: D004277:DNA, Single-Stranded; D012996:Solutions; D008274:Magnesium