Development of molecular separation / analysis device based on electrokinetic effects

本研究的目的是发展介电泳色谱，利用微细加工的电极在水溶液中产生高频强场，用于生物分子的介电分离和分析。该团队的重点是为实际应用开发原型，因此团队由来自大学和行业的研究人员组成。1)建立了基于PDMS的电极和流体通道的制作工艺，以及基于荧光的芯片上分子浓度定量测量方法。2)利用恒速流动的DEP色谱柱，实现了亲和素-生物素结合、DNA杂交和抗原-抗体结合的B/F分离。对于脉冲进样的DEP层析，使用了压力驱动的片上交叉进样器，该系统被证明是一种非常快速的分离大于几千碱基对的DNA的方法。3)提出了一种将透析膜集成到DEP层析芯片上的方法。该方法采用各向异性蚀刻而成的尖边开口，通过表面张力在其上形成渗析聚合物膜。结果表明，透析膜的性能满足DEP层析样品前处理的要求。

The purpose of this investigation is to develop dielectrophoretic chromatography, where high-frequency high- intensity field is created in aqueous solution using microfabricated electrodes, which is utilized for dielectrophoretic separation and assay of biological molecules. An emphasis is laid on the development of prototypes for practical application, so the team consists of researchers from both university and industry. The results obtained can be summarized as below :1) Fabrication process of the electrodes and PDMS-based fluid channels, as well as quantitative on-chip measurement method of molecular concentration based on fluorescence, are developed.2) With the DEP chromatography with a constant-velocity sample flow, B/F (Bound/Free) separation of avidin-biotin binding, DNA hybridization and antigen-antibody binding are experimentally demonstrated. For the DEP chromatography with pulse-wise injection, pressure-driven on-chip cross-injector is used, and the system is shown to be a very fast separation method for DNA larger than several kilo base-pairs. Its applicability to protein separation is also demonstrated.3) A method to integrate dialysis membrane onto the DEP chromatography chip is also developed. The method uses an opening with sharp edge fabricated by anisotropic etching, on which dialyzing polymer membrane is formed by surface tension. The performance of the dialysis membrane is shown to meet the requirement or the sample pre-treatment for the DEP chromatography.