Cell lysis for intracellular contents extraction is critical for biomedical sciences and clinical diagnostics. Plenty of chemical and physical cell lysis methods have been developed to achieve higher lysis efficiency and usability. In recent years, the emerging of microfluidic techniques has opened the possibility of integrating cell lysis and downstream analytical procedures into a small device. The miniaturization and integration result in plentiful advantages, such as time saving and the convenience of use. Among all microfluidic devices for cell lysis, the devices utilizing mechanical forces are superior due to the exemption from reagent residue and heating issues. Various mechanical cell lysis devices for targeting different contents have been demonstrated.

The thesis prese...[ Read more ]

Cell lysis for intracellular contents extraction is critical for biomedical sciences and clinical diagnostics. Plenty of chemical and physical cell lysis methods have been developed to achieve higher lysis efficiency and usability. In recent years, the emerging of microfluidic techniques has opened the possibility of integrating cell lysis and downstream analytical procedures into a small device. The miniaturization and integration result in plentiful advantages, such as time saving and the convenience of use. Among all microfluidic devices for cell lysis, the devices utilizing mechanical forces are superior due to the exemption from reagent residue and heating issues. Various mechanical cell lysis devices for targeting different contents have been demonstrated.

The thesis presents a microfluidic device for mechanical cell lysis and intracellular contents extraction. The device features point constrictions which are fairly short and highly localized. Little backpressure is generated and a local high stress field is created at the point constriction. Therefore cells are deformed and lysed by the high shear force when approaching the point constriction. Numerical simulation has been conducted and the results indicate that cells suffer from tremendous deformation when passing the constriction. The cell lysis process is recorded and lysis mechanisms are studied. The cell membrane is damaged and the nucleus is found to be isolated after the cell passing the constriction. The analysis of cell lysates by flow cytometer and microscope further confirms the existence of membrane debris and the nucleus extraction efficiency. Nucleus purification methods have been developed to remove membrane debris. Device performances over protein and DNA extraction have been investigated under different loading cell densities and device types. Quantification results of released protein and DNA from different types of cells further validate the wide applicability of the device.