Summary: Current Opinion in Colloid and Interface Science 9 (2004) 5358
1359-0294/04/$ - see front matter 2004 Elsevier Ltd. All rights reserved.
Competition between condensation of monovalent and multivalent ions
in DNA aggregation
Yoram Burak*, Gil Ariel, David Andelman
School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel
We discuss the distribution of ions around highly charged PEs when there is competition between monovalent and multivalent
ions, pointing out that in this case the number of condensed ions is sensitive to short-range interactions, salt and model-dependent
approximations. This sensitivity is discussed in the context of recent experiments on DNA aggregation, induced by multivalent
counterions such as spermine and spermidine.
2004 Elsevier Ltd. All rights reserved.
Keywords: DNA; Multivalent ions; Spermine
Despite extensive theoretical and experimental
research, polyelectrolyte (PE) solutions are relatively
poorly understood compared to their neutral counterparts
w1x. The main difficulty in their theoretical treatment
arises from the long-range nature of electrostatic inter-