Droplet Microfluidic Chip For Investigation Of Enzyme Activity And Encapsulation Of Human Cells

In recent years, droplet microfluidic chip is emerging as a novel biochemical analysis platform. Due to its advantages of high-efficiency, high-throughput, fast reaction time and low sample cost, there are numerous applications of this system, such as enzyme kinetics, single cell analysis, enzyme assay and DNA analysis and so on.In this article, we designed and fabricated a PDMS-based microfluidic chip that can generate droplets by hydrodynamic focusing. We hope this optimized structure can achieve a faster mixing efficiency so that we can use it more widely. At first, the investigation of mixing situation was carried out for the optimization of chip design. With the optimized droplet microfluidic chip, faster mixing of blue ink/water was successfully realized than the one designed before. So the analysis of enzyme activity by luminol/HRP chemiluminescence reaction was conducted on this optimized droplet microfluidic chip. Results indicated that when HRP was connected with a protein such as anti-IgG, the activity of it decreased quickly. By on-line dilution of reagents, we can achieve an Intensity-Concentration curve easily without changing the reagents. This method can be used to determine some enzyme activity. Then, we try the encapsulation of human cells with droplet, and select the suitable cell concentration to achieve one single cell in a droplet. It's an important part for further single cell analysis.