Separation of viable and nonviable mammalian cells using a deterministic lateral displacement microfluidic device

Abstract

Here, we present a deterministic lateral displacement (DLD) microfluidic device that may be used for label-free, passive, and continuous separation of viable and nonviable mammalian cells. Cells undergoing apoptosis (programmed cell death) become smaller than normal viable cells due to shrinkage and fragmentation. We used this distinct difference in size to selectively isolate viable Jurkat cells from nonviable apoptotic cells and their remnants through a DLD array that is capable of size-based fractionation of microparticles. First, we calibrated our DLD devices by separating a mixture of larger (∼15-μm) and smaller (∼8- or ∼10-μm) polystyrene beads that emulated viable and nonviable Jurkat cells, respectively. We then demonstrated the separation of viable and nonviable Jurkat cells by introducing their heterogeneous suspensions into two DLD devices with different design parameters. In a DLD device with a 20-μm gap, we collected viable cells at 100 ± 0% capture efficiency (n = 3), at a capture purity of 23.1 ± 4.8%, with 57.8 ± 8.1% removal efficiency of nonviable apoptotic cells and their remnants from the initial mixture solution. On a DLD device with a 23-μm gap, the capture purity of viable cells increased to 50.2 ± 15.0%, with 89.0 ± 3.5% removal efficiency of nonviable cells, and a lower capture efficiency of 48.2 ± 2.0% (n = 3). This first demonstration of label-free and passive separation of viable and nonviable cells by DLD illustrates its potential for, e.g., regenerative medicine and discovery of anti-cancer drugs.