Size-based chromosome separation in a microfluidic particle separation device using viscoelastic fluids

Viscoelastic flow-based particle manipulation techniques enable bio-particle focusing, separation, and enrichment by precisely tuning the rheological parameters, flow conditions, and microchannel geometry. In this study, we fabricated a PDMS-based single inlet/outlet microchannel to separate bio-particles by their size ranging from 1-10 μm. Flow conditions and rheological properties are optimized using 2 μm and 4 μm Polystyrene beads to reach the best particle separation condition. We demonstrated the size-based separation of human chromosomes by separating 1-2 μm size small chromosomes from 8-10 μm size large chromosomes. Thanks to its miniaturized size and simplicity, the isolation chip and unique viscoelastic separation method have great potential to be used as a future pioneering tool for genetic applications to study chromosome abnormalities such as fragile-X and trisomy.