title: Electrokinetic focusing and separation of mammalian cells in conductive biological fluids.
abstract: Active manipulation of cells, such as trapping, focusing, and isolation, is essential for various bioanalytical applications. Herein, we report a hybrid electrokinetic technique for manipulating mammalian cells in physiological fluids. This technique applies a combination of negative dielectrophoretic force and hydrodynamic drag force induced by electrohydrodynamics, which is effective in conductive biological fluids. With a three-electrode configuration, the stable equilibrium positions of cells can be adjusted for separation and focusing applications. Cancer cells and white blood cells can be positioned and isolated into specific locations in the microchannel under both static and dynamic flow conditions. To investigate the sensitivity of the hybrid electrokinetic process, AC voltage, frequency, and bias dependences of the cell velocity were studied systematically. The applicability of the hybrid electrokinetic technique for manipulating cells in physiological samples is demonstrated by continuous focusing of human breast adenocarcinoma spiked in urine, buffy coats, and processed blood samples with 98% capture efficiency.
authors.affiliation: Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.forename: Reza
authors.initials: R
authors.lastname: Riahi
authors.forename: Mandy L Y
authors.initials: ML
authors.lastname: Sin
authors.forename: Shufeng
authors.initials: S
authors.lastname: Zhang
authors.forename: Pak Kin
authors.initials: PK
authors.lastname: Wong
mesh_terms: D045744:Cell Line, Tumor; D002469:Cell Separation; D004566:Electrodes; D004912:Erythrocytes / Q000166:cytology*; D006046:Gold / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D046210:Microfluidic Analytical Techniques; D014025:Titanium / Q000737:chemistry
chemical_list: D006046:Gold; D014025:Titanium