Focusing and sorting of multiple-sized beads and cells using low-aspect-ratio spiral microchannels

A separation of Polystyrene micro-beads (PMBs) and natural Mast-cell tumor cells (MCTCs) of about 10-25 mu m diameter was performed using a microfluidic spiral microchannel. In this study, five-turned spiral microchannels were 500 mu m high and 130 mu m wide with an initial radius of curvature of 5.5 mm. Sorting efficacy of targeted PMB or MCTC samples of each size by focusing them into a single stream depended on the size of the samples and the flow rate. Flow cytometric analysis revealed that almost 90 % of PMBs and MCTCs of 15-25 mu m diameter could be successfully sorted from a mixture of smaller beads or cells at a flow rate of 1.0 mL/min.