Study on three-dimensional dielectrophoresis microfluidic chip for separation and enrichment of circulating tumor cells

Circulating tumor cells (CTCs) which means tumor cells shed into the peripheral blood of humans, are one of the important indicators in the early and accurate detection of malignancy. This paper is based on the principle of dielectrophoresis, the design and performance research of microfluidic microarray separating and enriching CTCs was carried out, and the separation and enriching of CTCs was realized by ultilizing the difference in dielectrophoretic force and the movement trajectories between CTCs and leukocytes. Chip structure design and optimization based on the COMSOL software simulation tool, through the separation experiment of human breast cancer cell MCF-7 and white blood cells, 60 kHz was selected as the frequency of cell separation experiment. Taking human liver cancer cell SMMC-7721 and human leukocyte mixture as the research object, the chip separation and enrichment experiment of CTCs was conducted. At 5 V voltage and 60 kHz frequency, the maximum separation flux of three-dimensional dielectrophores is microfluidic chip for human liver cancer cell SMMC-7721 reached 1.1 mL/h, and the separation efficiency was about 94%. The results of this research have important implications for separating, sorting and detecting CTCs.