Screening And Mechanical Properties Study Of Single Cell Using Microfluidic Chips

A single cell is the basic unit of life.With the iterative upgrade of microscope technology and the continuous improvement of the understanding of cell composition,people can more clearly recognize the similarities and differences between cells.At present,we can classify cells according to the source of the tissue,the characteristics of the cell itself,and cell secretions.This hierarchical phenomenon of cell population behavior helps to identify cell types related to disease and more accurately describe the interactions between cells.Single cell analysis technology based on microfluidics can realize a series of basic functions such as separation,screening,printing and detection at the single cell level.This article focuses on single cell screening and its mechanical performance measurement.In this paper,a microfluidic chip for single cell screening and printing and a microfluidic chip for measuring the mechanical properties of single cells are designed,and a device for experiment and measurement with the microfluidic chip is established.Fluorescence microscope,pressure-driven pump,and pressure sensor are a system of measuring devices,which realize the functions of screening,printing and measuring mechanical properties of single cell.Through experiments and numerical calculations,the relationship between the flow resistance,flow rate and air pressure of the pneumatic valve,and the relationship between the cell diameter and the critical pressure of the air pressure of the pneumatic valve are studied,and the feasibility of the single-cell screening idea based on double valves is verified.Experiments have verified the idea of using power-law rheological models and pressure sensors to measure the mechanical properties of single cells.The single-cell analysis platforms with microfluidic chip for single-cell screening,printing and mechanical property measurement have been established,which realized the function of screening and printing cells of a specific interval size.On this basis,a singlecell mechanical performance calculation algorithm based on the power-law rheological model and the definition of material Poisson's ratio was established.Experiments show that the average elastic modulus of BMSCs(Bone marrow mesenchymal stem cells)and Huh-7(Human liver cancer cell line)are 25.13 Pa and 69.74 Pa,K562(Human chronic myeloid leukemia cells),HUVECs(Human umbilical vein endothelial cells),BMSCs and Huh-7 Poisson's ratio measurement data have median values of 0.36,0.39,0.30,0.32 respectively.This system can realize the functions of single cell screening,printing and mechanical performance testing,and provides an effective research platform for future single cell analysis.