A low‐cost and high‐throughput benchtop cell sorter for isolating white blood cells from whole blood

Abstract

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 (i.e., 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 the developed 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 subpopulations 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 twofold 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 sorting of WBCs and also envisions broad potential sorting applications for other cell types.

Automatic Microfluidic Cell Wash Platform for Purifying Cells in Suspension: Puriogen

“…After Puriogen cell wash, the total count of live cells was changed from 1.53 × 10 6 to 1.34 × 10 6 . Considering the recovery ratio, the influence on the cell viability by Puriogen is below 1%, very similar to our previous cell viability analysis after size-based cell sorting . It is noted that the percentage of dead cells is decreased from 15.2 to 7.72%.…”

“…Before executing cell wash experiments, polystyrene particles were processed by our device to evaluate the wash efficiency. In our previous work, it has been shown that minimally 400 nm particles were confined in the side flow and hence drawn into the waste . In addition, the size of apoptotic bodies after cell death can be as small as 100 nm .…”

“…In our previous work, it has been shown that minimally 400 nm particles were confined in the side flow and hence drawn into the waste. 39 In addition, the size of apoptotic bodies after cell death can be as small as 100 nm. 47 Thus, 100 nm particles were used to test the efficiency of removal of cell debris with submicron sizes.…”

“…In this work, a similar microfluidic design was employed as the one in our previous work for separating different blood cells . The basic principle is that the F D , secondary flow drag force is introduced by utilizing the repeating curve channel (Figures a and S1a) to produce Dean flows. − The competence between F D and F L , (inertial lift force) will determine the final equilibrium particle positions.…”

“…The working principle of sharpening the sorting resolution with periodic contractions has been revealed in our previous work. 36,46 It has been explained that additional secondary flow and enhanced wallinduced lift force can make similarly sized particles more separable by shifting their equilibrium positions. The MCF-7 cells and 1 μm particles were mixed to simulate and test the separation performance by Puriogen and centrifuge (Figure 1c), which shows that most of the 1 μm particles have been removed and cells purified by Puriogen remain enormous amount of single-cell population.…”