Precise cell detecting and counting is meaningful in circulating tumor cells (CTCs) analysis. In this work, a simple cyclic olefin copolymer (COC) microflow cytometer device was developed for size-resolved CTCs counting. The proposed device is constructed by a counting channel and a pinched injection unit having three channels. Through injection flow rate control, microspheres/cells can be focused into the centerline of the counting channel. Polystyrene microspheres of 3, 9, 15, and 20 µm were used for the microspheres focusing characterization. After coupling to laser-induced fluorescence detection technique, the proposed device was used for polystyrene microspheres counting and sizing. A count accuracy up to 97.6% was obtained for microspheres. Moreover, the proposed microflow cytometer was applied to CTCs detecting and counting. To mimic blood sample containing CTCs and CTCs mixture with different subtypes, an MDA-MB-231 (human breast cell line) spiked red blood cells sample and a mixture of MDA-MB-231 and MCF-7 (human breast cell line) sample were prepared, respectively, and then analyzed by the developed pinched flow-based microfluidic cytometry. The simple fabricated and easy operating COC microflow cytometer exhibits the potential in the point-of-care clinical application.

中文翻译：

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基于捏流的微流控细胞计数循环肿瘤细胞的大小分辨计数

精确的细胞检测和计数在循环肿瘤细胞 (CTC) 分析中具有重要意义。在这项工作中，开发了一种简单的环烯烃共聚物 (COC) 微流式细胞仪装置，用于尺寸分辨的 CTC 计数。所提出的装置由计数通道和具有三个通道的夹紧注射单元构成。通过注射流速控制，微球/细胞可以聚焦到计数通道的中心线。3、9、15 和 20 µm 的聚苯乙烯微球用于微球聚焦表征。与激光诱导荧光检测技术耦合后，该装置可用于聚苯乙烯微球的计数和大小测量。微球的计数准确度高达 97.6%。此外，所提出的微流式细胞仪应用于 CTC 的检测和计数。为了模拟含有不同亚型的 CTC 和 CTC 混合物的血液样本，MDA-MB-231（人乳腺细胞系）加标红细胞样本以及 MDA-MB-231 和 MCF-7（人乳腺细胞系）样本的混合物分别制备，然后通过开发的基于捏流的微流控细胞术进行分析。简单制造和易于操作的 COC 微流式细胞仪展示了即时临床应用的潜力。