Shen Chaohua, Xu Peng, Huang Zhou, Cai Dongyang, Liu Shuang-Jiang, Du Wenbin
Department of Chemistry, Renmin University of China, 100872 Beijing, China.
Lab Chip. 2014 Aug 21;14(16):3074-80. doi: 10.1039/c4lc00213j.
This paper describes a simple and reusable microfluidic SlipChip device for studying bacterial chemotaxis based on free interface diffusion. The device consists of two glass plates with reconfigurable microwells and ducts, which can set up 20 parallel chemotaxis units as duplicates. In each unit, three nanoliter microwells and connecting ducts were assembled for pipette loading of a chemoeffector solution, bacterial suspension, and 1X PBS buffer solution. By a simple slipping operation, three microwells were disconnected from other units and interconnected by the ducts, which allowed the formation of diffusion concentration gradients of the chemoeffector for inducing cell migration from the cell microwell towards the other two microwells. The migration of cells in the microwells was monitored and accurately counted to evaluate chemotaxis. Moreover, the migrated cells were easily collected by pipetting for further studies after a slip step to reconnect the chemoeffector microwells. The performance of the device was characterized by comparing chemotaxis of two Escherichia coli species, using aspartic acid as the attractant and nitrate sulfate as the repellent. It also enables the separation of bacterial species from a mixture, based on the difference of chemotactic abilities, and collection of the cells with strong chemotactic phenomena for further studies off the chip.
本文描述了一种基于自由界面扩散用于研究细菌趋化性的简单且可重复使用的微流控滑移芯片装置。该装置由两块带有可重构微孔和微通道的玻璃板组成，可设置20个平行的趋化性单元作为复制品。在每个单元中，组装了三个纳升级微孔和连接微通道，用于通过移液器加载化学效应物溶液、细菌悬液和1X PBS缓冲溶液。通过简单的滑移操作，三个微孔与其他单元断开连接并通过微通道相互连接，这使得能够形成化学效应物的扩散浓度梯度，以诱导细胞从细胞微孔向其他两个微孔迁移。监测并准确计数微孔中细胞的迁移情况以评估趋化性。此外，在滑移步骤重新连接化学效应物微孔后，通过移液器很容易收集迁移的细胞以进行进一步研究。通过使用天冬氨酸作为引诱剂和硝酸硫酸盐作为驱避剂，比较两种大肠杆菌的趋化性来表征该装置的性能。它还能够基于趋化能力的差异从混合物中分离细菌种类，并收集具有强趋化现象的细胞以在芯片外进行进一步研究。
