Spectrophotometric analysis of nucleic acids: oxygenation-dependant hyperchromism of DNA

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• 作者：Rupak Doshi ; Philip J. R. Day ; Paolo Carampin ; Ewan Blanch ; Ian J. Stratford and Nicola Tirelli
• 关键词：DNA analysis ; DNA absorbance ; Charge– ; transfer complexes ; Hyperchromism ; Oxygenation
• 刊名：Analytical and Bioanalytical Chemistry
• 出版年：2010
• 出版时间：March, 2010
• 年：2010
• 卷：396
• 期：6
• 页码：2331-2339
• 全文大小：377.7 KB

文摘

The absorbance at 260 nm (A ₂₆₀) is ubiquitously used for nucleic acid quantification. We show that following oxygenation, DNA solutions experience alterations in both spectral properties (hyperchromism in the UV region, λ _max 260 nm) and DNA conformation. The spectral changes caused by oxygen–DNA complexation are stable for at least several weeks at room temperature or several hours at 37 ¡ãC, but are also reversible by purging with nitrogen. Our data indicate that DNA in working solutions might already exist in the oxygen-complexed state, potentially confounding spectrophotometric analyses. Further, the presence of these complexes does not appear to impart cell toxicity in vitro or affect the biophysical functional behaviour (e.g. hybridisation) of DNA. Interestingly, our work also suggests that hybridisation could determine a release of bound oxygen, a phenomenon that could open the way to the use of such systems as oxygen carriers.