Three-Differential White Blood Cell Count in Capillary Driven Image Flow Cytometry

White blood cells (WBCs) are a heterogeneous group of nucleated cells that play an important role in human health and immunity. Devices to measure total the WBC count and relative sub-type counts in a blood sample are widely used in diagnostic medicine to gain insight into the health of patients. We demonstrate an image-based flow cytometry method to determine the three-differential counts of lymphocytes, monocytes, and granulocytes, along with the total WBC count using acridine orange infused whole blood flowing through a microfluidic channel. A capillary driven microfluidic device is used, which has the advantage over conventional flow cytometry systems in terms of its small size, mechanical simplicity, and robustness making it suitable for use in portable point-of-care devices. Detection of the three classes of WBCs is done using a standard lab fluorescence microscope and imaging sensor.