Experimental Study Of Single Cell Separation And Storage Based On Microfluidic Pulse Drive

There are pressing needs in single cell analysis,and single cell analysis technologies are wildly applied in medicine and biology.Separating and encapsulating single cells into a microcapsule can improve the cross contamination that may exist in microarray chips and increase cell viability when culture for a long time.Altogether,it provides great convenience for long-term culture and analysis of single cell.Based on pulse driving technology of microfluid,an experimental system for preparing single-cell microcapsules was established,which have advantages of simple structure,flexible controllability and low cost.The electromagnet was selected as actuators to provide the pulse inertia force that is used for drivinig the fluid flow under the assistance of the driving control circuit and the corresponding mechanical structure.Then,the proportional relationship between the driving voltage applied at both ends of the electromagnet coil and the pulse inertia force was verified through the analysis of the principle of pulse inertial force generated by electromagnet.The normal micro-nozzle and the coaxial combined micro-nozzle for preparing microcapsules were fabricated in combination with heating-pull-off process and calcining process.Based on theoretical analysis and simulation of COMSOL Multiphysics,the flow principle and velocity characteristics and distribution of microfluids in two kinds of micro-nozzles were discussed.Besides,the jetting effects of coaxial combined micro-nozzles with different diameter ratio were simulated.The encapsulating material of the microcapsules herein is sodium alginate.The physical properties of the microcapsules prepared by different concentrations of sodium alginate were discussed,and normal micro-nozzles and coaxial combined micro-nozzles were used to prepare single-cell microcapsules respectively.Ultimately,the interval of the stable injection areas and optimal parameters for decreasing tailed-microcapsules were determined.In addition,the linear relationship between the microcapsule size and the driving voltage and the micro-nozzle diameter was given.Based on the obtained experimental parameters,the experiment of encapsulate single fish roe cell storagewas carried out.It was found that usinig coaxial combined micro-nozzles to encapsulate single fish roe cell has a better effect than that using normal micro-nozzles,and the single-cell encapsulating rates were 90.9% and 53.3%,respectively.