Single-cell manipulation and fluorescence detection in benchtop flow cytometry system with disposable plastic microfluidic chip

Flow cytometry and microfluidic system are versatile tools to study the functional genomics at the single-cell level in the postgenomic era. We have developed a microfluidics-based benchtop flow cytometry system incorporating a disposable plastic microchip and low-power diode lasers. The plastic microfluidic chip is designed and fabricated using soft lithography which enables the development of inexpensive and flexible miniaturized fluidic devices. The microchip contains the hydrodyamic focusing chamber where the sample and sheath fluids are driven by a pressure difference. The performance of the combined fluidics and optics is studied systematically to evaluate the detection accuracy and efficiency of our flow cytometry system. The interactions of the biological particles with surrounding squeezed flow and focused laser beam are investigated to optimize the design of the microchannel network as well as the optical characteristics of the instrument for efficient single-cell manipulation and detection.