nhancement of anion - exchange chromatography of DNA using 15 compaction agents

22 The use of adsorptive chromatography for preparative nucleic acid separations is often limited by low capacity. The 23 possibility that the adsorbent surface area sterically accessible to nucleic acid molecules could be increased by reducing their 24 radius of gyration with compaction agents has been investigated. The equilibrium adsorption capacity of Q-Sepharose 25 anion-exchange matrix for plasmid DNA at 600 mM NaCl was enhanced by up to ca. 40% in the presence of 2.5 mM 26 spermine. In addition, compaction agent selectivity has been demonstrated. Spermine, for example, enhances the adsorption 27 of both plasmid and genomic DNA, spermidine enhances binding only of plasmid, and hexamine2cobalt enhances only the 28 binding of genomic DNA. Compaction may be generally useful for enhancing adsorptive separations of nucleic acids. 29  2002 Published by Elsevier Science B.V.