Open AccessA synchrotron radiation X‐ray scattering study of aqueous solutions of native DNA
Author(s) -
Barone Giampaolo,
Sayers Zehra,
Svergun Dmitri,
Koch Michel H. J.
Publication year - 1999
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049599007463
Subject(s) - small angle x ray scattering , radius of gyration , scattering , synchrotron radiation , synchrotron , ionic bonding , x ray , gyration , small angle scattering , chemistry , materials science , virial coefficient , molecular physics , thermodynamics , optics , physics , polymer , ion , geometry , mathematics , organic chemistry
Synchrotron radiation small‐angle X‐ray scattering (SAXS) was used to investigate solutions of native DNA at different ionic strengths and temperatures. The mass per unit length, radius of gyration of the cross‐section of DNA and apparent second virial coefficient ( A 2 ) were obtained from Zimm plots in the rodlike particle approximation. The values of A 2 obtained in this way are positive and almost constant indicating that the repulsive interactions still influence the scattering patterns at resolutions as high as 5–8 nm. SAXS measurements in continuous temperature scans indicate that the rod approximation is valid over a wide temperature range during DNA melting and confirm that the rodlike–wormlike transition temperature increases with ionic strength.