Study On The Detection Method Of Circulating Tumor Cells Based On Microfluidic Chip

Cancer is the most threatening disease of human life and health,and the detection of circulating tumor cells has become the current research hotspot.With the gradual maturity of microfluidic technology,microfluidic chips have made great progress in life sciences.The current methods for detection of circulating tumor cells have the disadvantages of high equipment cost,poor detection effect,need for specific labeling of cells,and the like.Therefore,the use of microfluidic chip for the detection of circulating tumor cells has important theoretical value and practical significance.First,this article analyzed the dielectric properties of cells and the Coulter Principletheoretically,and the formula for cell-induced impedance changesis obtained by analyzing the DC and AC Coulter principles.Secondly,the mechanism of the fiber laser on the cells in the microchannel is analyzed theoretically,andbyanalyzingthe Rayleigh scattering,the Mie scattering,and the generalized Lorenz-Mie theory,the formulas for the laser-driven force of the cells are deduced.the formula for the driving effect of the fiber laser on the cells in the microfluidic was obtained by analyzing the forces acting on the cells in the microfluid theoretically.Then,using COMSOL Multiphysics software,the particle motion state and electric potential on the electrode surface in the electrode chip were simulated.In addition,the effect of the fiber laser force on cells in the fiber chip was simulated,and the factors affecting of cells sorting were analyzed by numerically simulating the particle trajectory.Two kinds of chips were designed based on the simulation results: one is the electrode chip for detecting circulating tumor cells;the other is the optical fiber chip for sorting circulating tumor cell.At the same time,the experimental system for detecting and sorting of circulating tumor cells was established.Finally,experiments were performed using 20 ?m diameter polystyrene microspheres instead of circulating tumor cells.In the experiment of detecting cell,compared with the impedance test results,the electrode chip was able to effectively detect the circulating tumor cells at the same injection rate.In the experiment of sorting cell,a 960 nm,300mW pump light source was used to drive the yeast cells in an open environment using an optical fiber,and yeast cells and 20-?m-diameter polystyrene microspheres were tested in the optical fiber chip.Different sizes of cells undergo lateral displacements at different distances to achieve the sorting of circulating tumor cells.On the basis of microfluidic chip,the detection of circulating tumor cells with low cost,no contact and no pollution has been realized by using Coulter Principle and optical fiber laser detection method.And it lays a certain foundation for the detection of cells in biomedicine in the future.