Improving the separation efficiency of DNA biosamples in capillary electrophoresis microchips using high-voltage pulsed DC electric fields

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• 作者：Che-Hsin Lin ; Jing-Hui Wang and Lung-Ming Fu
• 关键词：Pulsed electric field ; Separation efficiency ; Capillary electrophoresis chip
• 刊名：Microfluidics and Nanofluidics
• 出版年：2008
• 出版时间：September, 2008
• 年：2008
• 卷：5
• 期：3
• 页码：403-410
• 全文大小：451.6 KB
• 刊物类别：Engineering
• 刊物主题：Engineering Fluid Dynamics
  Medical Microbiology
  Polymer Sciences
  Nanotechnology
  Mechanics, Fluids and Thermodynamics
  Engineering Thermodynamics and Transport Phenomena
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1613-4990

文摘

This paper proposes a simple method for enhancing the separation efficiency of DNA biosamples in a capillary electrophoresis (CE) microchip by using high-voltage pulsed DC electric fields. A high-voltage amplifier is used to establish electric fields of up to 1 kHz to carry out CE separation; electrophoresis and electroosmotic effects are then pulsely induced. The experimental and numerical investigations commence by separating a mixed sample comprising two fluoresceins with virtually identical physical properties, namely Rhodamine B and Rhodamine 6G. It is found that the level of separation is approximately 2.1 times higher than that achieved using a conventional DC electric field of the same intensity. The performance of the proposed method is further evaluated by separating a DNA sample of HaeIII digested ΦX-174 ladder. The experimental results indicate that the separation level of the neighboring peaks 5a and 5b in the DNA marker is approximately 1.2, which is significantly higher than the value of 0.8 obtained using a CE scheme with a conventional DC electric field. The improved separation performance of the proposed pulsed DC electric field approach is attributed to a lower Joule heating effect as a result of a lower average power input and the opportunity for heat dissipation during the zero-voltage stage of the pulse cycle. Overall, the results demonstrate that the method proposed in this study provides a simple, low-cost technique for achieving a high separation performance in CE microchips.