title: Antibody-free isolation of rare cancer cells from blood based on 3D lateral dielectrophoresis.
abstract: We present an antibody-free approach for the high-purity and high-throughput dielectrophoretic (DEP) isolation of circulating tumour cells (CTCs) from blood in a microfluidic chip. A hydrodynamic sheath flow is designed upstream in the chip to direct the suspension samples to the channel side walls, thus providing a queue to allow DEP-induced lateral displacements. High-throughput continuous cancer cell sorting (maximum flow rate: ~2.4 mL h(-1), linear velocity: ~4 mm s(-1)) is achieved with a sustained 3D lateral DEP (LDEP) particle force normal to the continuous through-flow. This design allows the continuous fractionation of micro/nanosized particles into different downstream subchannels based on the differences in their different critical negative DEP strengths/mobilities. The main advantage of this separation strategy is that increasing the channel length can effectively increase the throughput proportionally. The effective separation of rare cancer cells (<0.001%) from diluted human blood in a handheld chip is demonstrated. An enrichment factor of 10(5) and a recovery rate of ~85% from a 0.001% cancer cell sample are achieved at an optimal flow rate of 20 μL min(-1) passing through a 6 cm long LDEP channel with an appropriate voltage at a frequency of 10 kHz. A higher throughput of 2.4 mL h(-1) is also achieved with a 13 cm long metal-based microchannel.
authors.affiliation: National Nano Device Laboratories, National Applied Research Laboratories, Tainan, Taiwan. ifcheng@narlabs.org.tw.
authors.forename: I-Fang
authors.initials: IF
authors.lastname: Cheng
authors.forename: Wei-Lun
authors.initials: WL
authors.lastname: Huang
authors.forename: Tzu-Ying
authors.initials: TY
authors.lastname: Chen
authors.forename: Chien-Wei
authors.initials: CW
authors.lastname: Liu
authors.forename: Yu-De
authors.initials: YD
authors.lastname: Lin
authors.forename: Wu-Chou
authors.initials: WC
authors.lastname: Su
mesh_terms: D002469:Cell Separation / Q000295:instrumentation* / Q000379:methods*; D004586:Electrophoresis / Q000295:instrumentation; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D009360:Neoplastic Cells, Circulating / Q000473:pathology*