Design And Preparation Of PDMS Microfluidic Chip And Its Application In Single Cell Separation And Analysis

Single-cell analysis provides a powerful technology tool for life science and biomedical applications. Traditional methods for single-cell isolation such as serial dilution, micromanipulation, optical tweezers, flow cytometry and microfluidics suffered from tedious operation or expensive equipment. In this paper, a facile droplet-sorting-based single-cell isolation and dispensing platform was innovatively developed.In chapter 1, the state-of-art of single-cell isolation methods was reviewed, as well as a variety of microfluidic-based single-cell manipulation techniques.In chapter 2, the materials and fabrication methods of microfluidic chip used in this paper were introduced.In chapter 3, a simple, low-cost and on-demand microfluidic controlling platform was developed based on a unique capillary-tuned solenoid microvalve suction effect without any outer pressure source. The suction effect was innovatively employed as a stable and controllable driving force for the manipulation of the microfluidic system. Several important microfluidic unit operations such as cell/droplet sorting and on-demand sizecontrollable droplet generation have been demonstrated on the developed platform and both simulations and experiments confirmed this platform with good controllability and stability.In chapter 4, a facile droplet-sorting-based single-cell isolation was presented. The platform innovatively integrated a capillary-tuned solenoid valve suction and a capillary chip-to-world interface for sorting and dispensing single-cell droplet. The results demonstrated that the suction force originated from the capillary-tuned valve was stable and controllable for droplet sorting without any other outer pressure sources, and over 90% of the dispensed droplets contained single-cell and the viability of these single cells was 80%. Real-time qPCR and whole genome amplification of single-cell samples obtained from our platform was successfully performed. This easy-to-use and low-cost platform is promising to speed up the progress of single-cell analysis.