A Novel and Robust Single-cell Trapping Method on Digital Microfluidics
Jiao Zhai,
Haoran Li,
Ada Hang Heng Wong,
Cheng Dong,
Shuhong Yi,
Yanwei Jia,
Pui-In Mak,
Chuxia Deng,
Rui Martins
Affiliations
Jiao Zhai
State-Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macao SAR, China
Haoran Li
State-Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macao SAR, ChinaFaculty of Science and Technology-ECE, University of Macau, Macau SAR, China
Ada Hang Heng Wong
Cancer Center, Faculty of Health Sciences, University of Macau, Macau, Macao
Cheng Dong
State-Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics,, University of Macau, Macao SAR, China
Shuhong Yi
Liver Transplantation Center, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510000, China
Yanwei Jia
State-Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macao SAR, ChinaFaculty of Science and Technology-ECE, University of Macau, Macau SAR, China, Cancer Center, Faculty of Health Sciences, University of Macau, Macau, China
Pui-In Mak
State-Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macao SAR, ChinaFaculty of Science and Technology-ECE, University of Macau, Macau SAR, China
Chuxia Deng
Cancer Center, Faculty of Health Sciences, University of Macau, Macau, China
Rui Martins
State-Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Macao SAR, ChinaFaculty of Science and Technology-ECE, University of Macau, Macau SAR, China, Instituto Superior Técnico, Universidade de Lisboa, Portugal
Due to cell heterogeneity, the differences among individual cells are averaged out in bulk analysis methods, especially in the analysis of primary tumor biopsy samples from patients. To deeply understand the cell-to-cell variation in a primary tumor, single-cell culture and analysis with limited amount of cells are in high demand. Microfluidics has been an optimum platform to address the issue given its small reaction volume requirements. Digital microfluidics, which utilizes an electric signal to manipulate individual droplets has shown promise in cell-culture with easy controls. In this work, we realize single cell trapping on digital microfluidic platform by fabricating 3D microstructures on-chip to form semi-closed micro-wells. With this design, 20% of 30 x 30 array can be occupied by isolated single cells. We also use a low evaporation silicon oil and a fluorinated surfactant to lower the droplet actuation voltage and prevent the drop from evaporation, while allowing cell respiration during the long term of culture (24 h). The main steps for single cell trapping on digital microfluidics, as illustrated in this protocol, include 3D microstructures design, 3D microstructures construction on chip and oil film with surfactant for single cell trapping on chip.