The efficient purification and analysis of topological DNA variants is mandatory for many state-of-the-art molecular medicine technologies, like gene- and cancer-therapy as well as plasmid vaccination. In this work, we exploit dielectrophoresis (DEP) for a fast and efficient continuous-flow separation and analysis that goes beyond the standard methods of gel electrophoresis and capillary electrophoresis. The aim of this work was to reach for the limits in dielectrophoretic analysis of DNA regarding the size resolution and the topological conformation. A continuous-flow analytical separation of analyte mixtures of small linear DNA-fragments (10.0 kbp, 8.0 kbp, 6.0 kbp, and 5.0 kbp) and topological DNA variants (linear and supercoiled conformation) was investigated. We present a world record in the minimal size difference of 16.7% of DNA samples that can be resolved in a dielectrophoretic continuous-flow separation. Moreover, we demonstrate for the first time a microfluidic continuous-flow separation of DNA molecules based on their topological conformation. Since dielectrophoresis is virtually label-free, it offers a fast in-process quality control with low consumption, e.g. for the production of gene vaccines.

中文翻译：

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达到连续流动介电泳DNA分析的极限

对于许多最先进的分子医学技术，例如基因治疗和癌症治疗以及质粒疫苗接种，必须对拓扑DNA变体进行有效的纯化和分析。在这项工作中，我们利用介电电泳（DEP）进行快速有效的连续流分离和分析，这超出了凝胶电泳和毛细管电泳的标准方法。这项工作的目的是在DNA的介电泳分析中达到关于大小分辨率和拓扑构象的极限。对小线性DNA片段（10.0 kbp，8.0 kbp，6.0 kbp和5.0 kbp）和拓扑DNA变体（线性和超螺旋构象）的分析物混合物进行连续流分析分离。我们以16的最小尺寸差异创造了世界纪录。可在介电泳连续流分离中分离的DNA样品的7％。此外，我们首次展示了基于DNA分子拓扑构象的微流体连续流分离。由于介电泳几乎没有标签，因此可以快速进行过程中的质量控制，且消耗低，例如用于生产基因疫苗。