DNA Compaction onto Hydrophobic Surfaces by Different Cationic Surfactants

Author(s): Cárdenas, Marité, Tommy Nylander, R. K. Thomas, Björn Lindman

Journal: Langmuir (2005) 21: 6495-6502.

Abstract:
DNA compaction by alkyltrimethylammonium surfactants at hydrophobized silica surfaces and the effect of the counterion, as well as the hydrocarbon chain length,wasinvestigated by in situ null-ellipsometry. In addition, DNA compaction in the presence of a gemini surfactant, hexyl-α,ω-bis(dodecyldimethylammonium bromide), was studied. The type of cationic amphiphile used was found not to have a pronounced effect on the mixedDNA-cationic surfactant adsorbed layer thickness, although the surface concentration excess for the mixed layers seemed to follow the same trend as that for DNA-free surfactant layers. Interestingly, it was also found that the stability of the mixed adsorbed layer largely depends on the cationic surfactant used.