Numerous microfluidic separation applications have been shown in the past years providing a fast analysis of biological samples like DNA or proteins. Microfluidic separation based on dielectrophoresis (DEP), that is the migration of a polarizable object in an inhomogeneous electric field, provides numerous advantages. However, the main drawback of DEP separation devices is that they are not sufficient for large-scale sample purification due to the lack of high sample throughput. In this work, we present for the first time a microfluidic device with two parallelized dielectrophoretic separations of (biological) samples smaller than 1 µm. The separation is carried out by means of insulator-based DEP, that is an insulating ridge reduced the flow through height and thus created a nanoslit at which the selective DEP forces occur. The device consists of a cross injector, two parallel operation regions and separate harvesting reservoirs where the samples are collected. Each DEP operation region contains an insulating ridge. We successfully demonstrate the separation of 100 and 40 nm beads and 10 and 5 kbp DNA with a separation purity of more than 80%. This states the proof-of-concept for up-scaling of dielectrophoretic separation by parallelization. As the present technique is virtually label-free, it offers a fast purification, for example in the production of gene vaccines.

中文翻译：

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DNA 的并行连续流介电泳分离

在过去的几年中，已经出现了大量的微流体分离应用，可以对 DNA 或蛋白质等生物样品进行快速分析。基于介电电泳（DEP）的微流体分离，即可极化物体在不均匀电场中的迁移，具有许多优点。然而，DEP分离装置的主要缺点是由于缺乏高样品通量，不足以进行大规模样品纯化。在这项工作中，我们首次提出了一种微流体装置，可对小于 1 µm 的（生物）样品进行两次并行介电泳分离。分离是通过基于绝缘体的 DEP 进行的，即绝缘脊降低了流经高度，从而产生了纳米狭缝，选择性 DEP 力发生在纳米狭缝上。该装置由交叉注射器、两个并行操作区域和收集样品的独立收集容器组成。每个DEP操作区域包含一个绝缘脊。我们成功演示了 100 和 40 nm 珠子以及 10 和 5 kbp DNA 的分离，分离纯度超过 80%。这说明了通过并行化扩大介电泳分离的概念验证。由于目前的技术实际上是无标记的，因此它提供了快速纯化，例如在基因疫苗的生产中。这说明了通过并行化扩大介电泳分离的概念验证。由于目前的技术实际上是无标记的，因此它提供了快速纯化，例如在基因疫苗的生产中。这说明了通过并行化扩大介电泳分离的概念验证。由于目前的技术实际上是无标记的，因此它提供了快速纯化，例如在基因疫苗的生产中。