A microfluidic chip for capturing, imaging and counting CD3+ T-lymphocytes and CD19+ B-lymphocytes from whole blood

•We propose a pillar-based microfluidic device to separate leukocytes from whole blood high efficiently without clogging.•We could obtain the count and ratio of T and B cells from whole blood and compared the results to those obtained using a flow cytometer.•We achieved 99.8% efficiency in capturing leukocytes using the microfluidic chip,•The ratio of CD3+ and CD19+ had a coefficient of r = 0.9876 and a coefficient of variation of 2.77%, from 1 μL of whole blood sample.