An integrated opto-microfluidic device for microflow cytometry

Microflow cytometry has become an attractive tool for counting and analysis of complex cell population and finds many applications in life science research. However, its implementation in screening small sized targets, such as microorganisms, is limited by challenges associated with sample handling and detection in a flow. Here, we report the function of a 3D flow focusing microfluidic system as a high performance, multi-parameter flow cytometry. The system consists of a detection chamber that can precisely control a highly focused sample flow in 3D and an integrated optical fiber to collect the scattered light at the vertical plane. The ability of the system to detect small beads (1 µm), differentiate subtle differences (2 µm) and accurately profile a mixed bead population is demonstrated. Furthermore, multiple types of information about the sample, including the inherent biochemical information (e.g., fluorescence or Raman signal) and physical properties (e.g., size) are simultaneously generated, allowing sophisticated cellular analysis. Together with the facile and robust operation, this provides a versatile tool that could be used for multi-parametric analyses in a diversity of applications.