Label-free blood cells separation and enrichment from whole blood by high-throughput hydrodynamic and inertial force

Abstract

White blood cells or rare cells such as cancer cells with red blood cells in the whole blood, the concentration difference is approximately 1000 times in whole blood. To handle this extremely large cells population in microfluidic chip, we created a microdevice that takes advantage of the intrinsic features of blood flow in the microcirculation to separate leukocytes from whole blood, and solve clogging problem due to the large amount of blood cells (10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8-9</sup> cell/ml) by high-throughput hydrodynamic separation in microchannel. Results also showed high separation efficiency of blood cells by inertial force in microfluidics that containing high concentration whole blood cells (4.3×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> cells/μl). We demonstrated whole blood human separation in double layer structured microfluidic devices, utilizing the principle of hydrodynamic inertial forces to separate red blood cells from whole blood and enrich leukocytes (white blood cells) extracting by the elastic properties of blood cell and the inertial force, like shear lift force in a continuous flow separation, a high separation efficiency (~92%) and high throughput flow rate (10 mL, 300 μl/s) was obtained in this microfluidic chip.