关键词: 微流控芯片, 单细胞, 装样, 溶膜

Abstract: A microfluidic system was developed for the analysis of single biological cells, with functional integration of cell sampling, single cell loading, docking, lysing, and capillary electrophoretic separation in microfabricated channels on a single glass chip. Channels were 12 μm deep and 75μm wide, with a double-Tdesign cell injector that was directly connected to a capillary electrophoretic separation channel with an effective separation length of 37 mm. During sampling with a cell suspension (cell population 1. 2×10⁵cells/mLin physiological salt solution), differential hydrostatic pressure (created by adjusting liquid levels in the four reservoirs) was used to control cell flow exclusively through the 200 μm channel between the two T-junctions. Single cell loading into the separation channel was achieved by electrophoretic means by applying a set of potentials at the four reservoirs, counteracting the hydrostatic flow. Aspecial docking (adhering) procedure for the loaded cell was applied through flow control to affect cell lysis at the applied CE separation voltage(1. 4 kV) within the working electrolyte(pH 9. 2 borate buffer) without additional lysates. The docked lysing approach reduced dispersion of released intracellular constituents, and significantly improved the CEseparation efficiency. FITC-labeled components in the cellular membrane of single human erythrocyte cells were detected by using laser induced fluorescence. Aretention time precision of 0. 9% RSD(n=4) for FITC, and an average separation efficiency of 18 μm plate height for FITCwere achieved.

Key words: Microfluidic chip, Single cell, Loading, Lysing