A microchip electrophoresis-mass spectrometric platform with double cell lysis nano-electrodes for automated single cell analysis.
A microchip electrophoresis-mass spectrometric platform with double cell lysis nano-electrodes for automated single cell analysis.
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DOI：
10.1016/j.chroma.2016.05.015
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发表时间：
2016-06-17
期刊：
影响因子：
--
通讯作者：
Liu YM
中科院分区：
文献类型：
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作者：
Li X;Zhao S;Hu H;Liu YM
基于毛细管电泳的单细胞分析已成为细胞水平研究的重要手段。然而，由于难以控制注射的细胞数量以及与细胞聚集相关的不可再现性，单细胞分析的自动化一直是一个挑战。在此，我们报告了一种新的微流控平台的发展部署双纳米电极细胞裂解技术的单细胞自动分析与质谱检测。所提出的微流控芯片集成了用于快速单细胞裂解的细胞大小的高压区、用于电泳分离的微流控通道和用于MS检测中电离的纳米电喷雾发射器。在此基础上，建立了单细胞自动分析的微芯片电泳-质谱联用技术。在该方法中，细胞引入、细胞裂解和MCE-MS分离是计算机控制的，并作为一个循环整合到连续测定中。对大量的PC-12神经元细胞（完整的和暴露于25 mM KCl的）进行分析，以确定多巴胺（DA）和谷氨酸（Glu）的细胞内水平。结果表明，PC-12细胞内DA含量高于Glu含量，且两者在细胞间存在差异。细胞内DA/Glu比值为4.20 ± 0.8（n=150）。有趣的是，在细胞暴露于25 mM KCl 8 min后，该比率急剧下降至0.38 ± 0.20（n= 150），表明细胞迅速且大量地释放DA，而它们响应于KCl诱导的去极化以慢得多的速度释放Glu。这些结果表明，所提出的MCE-MS分析平台在细胞水平的研究中可能具有很大的潜力。
Capillary electrophoresis-based single cell analysis has become an essential approach in researches at the cellular level. However, automation of single cell analysis has been a challenge due to the difficulty to control the number of cells injected and the irreproducibility associated with cell aggregation. Herein we report the development of a new microfluidic platform deploying the double nano-electrode cell lysis technique for automated analysis of single cells with mass spectrometric detection. The proposed microfluidic chip features integration of a cell-sized high voltage zone for quick single cell lysis, a microfluidic channel for electrophoretic separation, and a nanoelectrospray emitter for ionization in MS detection. Built upon this platform, a microchip electrophoresis - mass spectrometric method (MCE-MS) has been developed for automated single cell analysis. In the method, cell introduction, cell lysis, and MCE-MS separation are computer controlled and integrated as a cycle into consecutive assays. Analysis of large numbers of individual PC-12 neuronal cells (both intact and exposed to 25 mM KCl) was carried out to determine intracellular levels of dopamine (DA) and glutamic acid (Glu). It was found that DA content in PC-12 cells was higher than Glu content, and both varied from cell to cell. The ratio of intracellular DA to Glu was 4.20 ± 0.8 (n=150). Interestingly, the ratio drastically decreased to 0.38 ± 0.20 (n= 150) after the cells are exposed to 25 mM KCl for 8 min, suggesting the cells released DA promptly and heavily while they released Glu at a much slower pace in response to KCl-induced depolarization. These results indicate that the proposed MCE-MS analytical platform may have a great potential in researches at the cellular level.