Size-based cell sorting by deterministic lateral displacement

Abstract

Microfluidic devices offer several advantages over conventional, large scale cell sorting systems. Creating microfluidics technology for lab-on-a-chip adaptations of these systems provides several benefits: simplicity of operation, improved transport control, portability, greater accessibility, reduced cost and potential for integration with other analytical techniques. This technology supplies important tools for biomedical applications such as tissue culture, drug discovery and point-of-care diagnostic systems. This work presents a microfluidic device which uses asymmetric bifurcation of laminar flow around objects for the continuous separation of cell subpopulation from a heterogeneous cell suspension. Based on their size, each cell chooses its path through the device deterministically. Thus theoretically, all cells of the same size would follow the same path resulting in high resolution. This study investigates the effect of various design parameters on the performance of the microfluidic chip using experimental methods. The microfluidic devices were manufactured from poly(dimethyl) siloxane (PDMS) using patterned silicon wafers by replica molding. Experiments were conducted using spherical mammalian cells and the cell movement was observed under a microscope. The cell movement within the device was disrupted repeatedly during the experiments because of cell clumping and the flexible nature of the cells. Nevertheless, the cells were observed to be laterally displaced and fractionation of the input sample was observed.