LAUSR

The ability to isolate and purify white blood cells (WBCs) from mixed ensembles such as blood would benefit autologous cell-based therapeutics as well as diagnosis of WBC disorders. Current WBCs isolation methods have the limitations of low purity or requiring complex and expensive equipment. In addition, due to the overlap in size distribution between lymphocytes (a sub-population of WBCs) and red blood cells (RBCs), it is challenging to achieve isolation of entire WBCs populations. In this work, we developed an inertial microfluidics-based cell sorter, which enables size-based, high-throughput isolation and enrichment of WBCs from RBC-lysed whole blood. Using inertial microfluidic chip, the sorting resolution is sharpened within 2 μm, which achieved separation between 3 and 5 μm diameter particles. Thus, with the present cell sorter, a full population of WBCs can be isolated from RBC-lysed blood samples with recovery ratio of 92%, and merely 5% difference in the composition percentage of the three sub-populations of granulocytes, monocytes and lymphocytes compared to the original sample. Furthermore, our cell sorter is designed to enable broad application of size-based inertial cell sorting by supplying a series of microchips with different sorting cutoff size. This strategy allows us to further enrich the lymphocytes population by two-folds using another microchip with a cutoff size between 10 and 15 μm. With simplicity and efficiency, our cell sorter provides a powerful platform for isolating and sub-sorting of WBCs and also envisions broad potential applications in other types of cell sorting at low cost. Additional supporting information may be found in the online version of this article at the publisher's web-site. Color online: See article online to view Figs. 1-8 in color. This article is protected by copyright. All rights reserved.