An optofluidic approach to miniature flow cytometry

Flow cytometry is a powerful high-throughput single-cell characterization tool that has significant impact on both biomedical research and clinical diagnostics. In flow cytometry, the analysis is performed by passing a narrow stream of cells through a focused laser beam at a rate of thousands of cells per second. Information regarding the size, type, and contents of cells can be subsequently derived through the analyses of the excited fluorescence emission or scattered light arising from each individual cell. In the past decade, flow cytometry has undergone remarkable advancements. It offers reliable, high-throughput, high-accuracy single-cell analyses for a wide variety of biomedical studies. It has also quickly become the method of choice for many clinical diagnostics, ranging from routine blood tests to diagnoses of lethal diseases such as leukemia and HIV. However, as of now the full potential of flow cytometry as a clinical diagnostic tool has yet to be realized. Its high cost (generally > $100,000), mechanical complexity, bulky size, and need for highly trained personnel have limited its usage. Therefore there is an incentive to develop affordable, highly integrated, miniaturized flow cytometry systems.