title: Inertial microfluidics for sheath-less high-throughput flow cytometry.
abstract: Flow cytometer is a powerful single cell analysis tool that allows multi-parametric study of suspended cells. Most commercial flow cytometers available today are bulky, expensive instruments requiring high maintenance costs and specially trained personnel for operation. Hence, there is a need to develop a low cost, portable alternative that will aid in making this powerful research tool more accessible. In this paper we describe a sheath-less, on-chip flow cytometry system based on the principle of Dean coupled inertial microfluidics. The design takes advantage of the Dean drag and inertial lift forces acting on particles flowing through a spiral microchannel to focus them in 3-D at a single position across the microchannel cross-section. Unlike the previously reported micro-flow cytometers, the developed system relies entirely on the microchannel geometry for particle focusing, eliminating the need for complex microchannel designs and additional microfluidic plumbing associated with sheath-based techniques. In this work, a 10-loop spiral microchannel 100 microm wide and 50 microm high was used to focus 6 microm particles in 3-D. The focused particle stream was detected with a laser induced fluorescence (LIF) setup. The microfluidic system was shown to have a high throughput of 2,100 particles/sec. Finally, the viability of the developed technique for cell counting was demonstrated using SH-SY5Y neuroblastoma cells. The passive focusing principle and the planar nature of the described design will permit easy integration with existing lab-on-a-chip (LOC) systems.
authors: Department of Electrical and Computer Engineering, University of Cincinnati, Cincinnati, OH 45221, USA.
authors: Ali Asgar S
authors: AA
authors: Bhagat
authors: Sathyakumar S
authors: SS
authors: Kuntaegowdanahalli
authors: Necati
authors: N
authors: Kaval
authors: Carl J
authors: CJ
authors: Seliskar
authors: Ian
authors: I
authors: Papautsky
mesh_terms: D002452:Cell Count / Q000379:methods; D005434:Flow Cytometry / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D046208:Microchip Analytical Procedures / Q000379:methods*; D044085:Microfluidics / Q000295:instrumentation* / Q000379:methods*