Negative selection-based circulating tumor cell (CTC) isolation is able to harvest viable, label-free, and clinically meaningful CTCs from the cancer patients’ blood. Nevertheless, its main shortcoming is its inability to isolate high-purity CTCs, restricting subsequent CTC-related analysis. To address this issue, this study proposed a two-step optically-induced dielectrophoresis (ODEP) cell manipulation to process the cell sample harvested by negative selection-/immunomagnetic microbeads-based CTC isolation. The working mechanism is that the ODEP force acting on the cells with and without magnetic microbeads binding is different. Accordingly, the use of ODEP cell manipulation in a microfluidic system was designed to first separate and then isolate the cancer cells from other magnetic microbead-bound cells. Immunofluorescent microscopic observation and ODEP cell manipulation were then performed to refine the purity of the cancer cells. In this study, the optimum operating conditions for effective cell isolation were determined experimentally. The results revealed that the presented method was able to further refine the purity of cancer cell in the sample obtained after negative selection-based CTC isolation with high cell purity (81.6~86.1%). Overall, this study proposed the combination of immunomagnetic bead-based cell isolation and ODEP cell manipulation for the negative selection-based isolation of CTCs.

中文翻译：

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基于免疫磁珠的细胞分离和基于光诱导介电电泳 (ODEP) 的微流体装置相结合，用于基于负选择的循环肿瘤细胞 (CTC) 分离


基于负选择的循环肿瘤细胞 (CTC) 分离能够从癌症患者的血液中收获活的、无标记的且具有临床意义的 CTC。然而，其主要缺点是无法分离高纯度的CTC，限制了后续CTC相关分析。为了解决这个问题，本研究提出了一种两步光诱导介电电泳 (ODEP) 细胞操作来处理通过基于负选择/免疫磁性微珠的 CTC 分离收获的细胞样品。其工作机制是有磁性微珠与没有磁性微珠结合的细胞作用的ODEP力不同。因此，在微流体系统中使用 ODEP 细胞操作的目的是首先将癌细胞与其他磁性微珠结合的细胞分离，然后分离。然后进行免疫荧光显微镜观察和 ODEP 细胞操作以提高癌细胞的纯度。在本研究中，通过实验确定了有效细胞分离的最佳操作条件。结果表明，该方法能够进一步精炼基于负选择的CTC分离后获得的样品中癌细胞的纯度，细胞纯度较高（81.6~86.1%）。总体而言，本研究提出将基于免疫磁珠的细胞分离和 ODEP 细胞操作相结合，用于基于负选择的 CTC 分离。