DNA Compaction at Hydrophobic Surfaces Induced by a Cationic Amphiphile

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• 作者：Marité ; Cá ; rdenas ; Alan Braem ; Tommy Nylander ; and Bjö ; rn Lindman
• 刊名：Langmuir
• 出版年：2003
• 出版时间：September 16, 2003
• 年：2003
• 卷：19
• 期：19
• 页码：7712 - 7718
• 全文大小：147K
• 年卷期：v.19,no.19(September 16, 2003)
• ISSN：1520-5827

文摘

Cetyltrimethylammonium bromide (CTAB) induces partially irreversible compaction of DNA-adsorbedlayers on hydrophobic silica. Additionally, there is a synergistic increase in the adsorbed amount whenboth CTAB and DNA are present as compared to the surface excess concentration of either of the individualcomponents. In this study of the DNA adsorption and DNA-CTAB coadsorption by ellipsometry, emphasishas been placed on the DNA molecular weight as well as its conformation (single and double stranded).The DNA molecular weight and conformation have a large effect on the surfactant-free DNA adsorptionbehavior but not on the mixed DNA-CTAB adsorption behavior. Comparison between interfacial and bulkcomplexation has been made where possible. The DNA-CTAB complexes at the interface are neutraldespite the large excess of DNA in the bulk. The final structure of the adsorbed layer was found to bedependent on the history of complex formation and DNA size.