Pressure-Induced Transport of DNA Confined in Narrow Capillary Channels

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• 作者：Xiayan Wang ; Lei Liu ; Qiaosheng Pu ; Zaifang Zhu ; Guangsheng Guo ; Hui Zhong ; Shaorong Liu
• 刊名：The Journal of the American Chemical Society
• 出版年：2012
• 出版时间：May 2, 2012
• 年：2012
• 卷：134
• 期：17
• 页码：7400-7405
• 全文大小：368K
• 年卷期：v.134,no.17(May 2, 2012)
• ISSN：1520-5126

文摘

Pressure-induced transport of double-stranded DNA (dsDNA) from 10 base pairs (bp) to 1.9 mega base pairs (Mbp) confined in a 750-nm-radius capillary was studied using a hydrodynamic chromatographic technique and four distinct length regions (rod-like, free-coiled, constant mobility, and transition regions) were observed. The transport behavior varied closely with region changes. The rod-like region consisted of DNA shorter than the persistence length (150 bp) of dsDNA, and these molecules behaved like polymer rods. Free-coiled region consisted of DNA from 150 bp to 2 kilo base pairs (kbp), and the effective hydrodynamic radius R_HD of these DNA scaled to L^0.5 (L is the DNA length in kbp), a characteristic property of freely coiled polymers. Constant mobility region consisted of DNA longer than 100 kbp, and these DNA had a constant hydrodynamic mobility and could not be resolved. Transition region existed between free-coiled and constant mobility regions. The transport mechanism of DNA in this region was complicated, and a general empirical equation was established to relate the mobility with DNA length. Understanding of the fundamental principles of DNA transport in narrow capillary channels will be of great interest in the development of 鈥渓ab-on-chip鈥?technologies and nongel DNA separations.