The application of fluorescence correlation spectroscopy in detecting DNA condensation

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• 作者：Kral ; Teresa ; Langner ; Marek ; Bene&scaron ; Martin ; Baczynska ; Dagmara ; Ugorski ; Maciej ; Hof ; Martin
• 关键词：Plasmid condensation ; Ethidium bromide ; Propidium iodide ; FCS ; Spermine ; Hexadecyltrimethyl ammonium bromide
• 刊名：Biophysical Chemistry
• 出版年：2002
• 出版时间：February 19, 2002
• 年：2002
• 卷：95
• 期：2
• 页码：135-144
• 全文大小：332 K

文摘

We report the application of fluorescence correlation spectroscopy (FCS) in characterizing conformational changes (condensation) of chemically well-defined DNA plasmids. The plasmids: pHβAPr-1-neo (10 kbp, contour length 3.4 μm) and pBluescript SKt (2.96 kbp, contour length 1.02 μm) were imaged by a confocal fluorescence microscope using two fluorescent probes: ethidium bromide (EtBr) and propidium iodide (PrIo). It became clear that the DNA molecule exhibits discrete conformational change between the coil and globule states with the addition of a small amount (the order of magnitude being 10⁻⁵ M) of cationic surfactant, spermine and hexadecyltrimethyl ammonium bromide (HTAB). When the concentrations of both condensing agents are smaller than 6.0×10⁻⁶ M and 2.0×10⁻⁶ M for the 10 and 2.96 kbp, both plasmids are in the extended coil state with diffusion constants D_{10 kbp}