title: High-throughput rare cell separation from blood samples using steric hindrance and inertial microfluidics.
abstract: The presence and quantity of rare cells in the bloodstream of cancer patients provide a potentially accessible source for the early detection of invasive cancer and for monitoring the treatment of advanced diseases. The separation of rare cells from peripheral blood, as a "virtual and real-time liquid biopsy", is expected to replace conventional tissue biopsies of metastatic tumors for therapy guidance. However, technical obstacles, similar to looking for a needle in a haystack, have hindered the broad clinical utility of this method. In this study, we developed a multistage microfluidic device for continuous label-free separation and enrichment of rare cells from blood samples based on cell size and deformability. We successfully separated tumor cells (MCF-7 and HeLa cells) and leukemic (K562) cells spiked in diluted whole blood using a unique complementary combination of inertial microfluidics and steric hindrance in a microfluidic system. The processing parameters of the inertial focusing and steric hindrance regions were optimized to achieve high-throughput and high-efficiency separation, significant advantages compared with existing rare cell isolation technologies. The results from experiments with rare cells spiked in 1% hematocrit blood indicated >90% cell recovery at a throughput of 2.24 × 10(7) cells min(-1). The enrichment of rare cells was >2.02 × 10(5)-fold. Thus, this microfluidic system driven by purely hydrodynamic forces has practical potential to be applied either alone or as a sample preparation platform for fundamental studies and clinical applications.
authors.affiliation: College of Science, Northwest A&F University, Yangling, Shaanxi 712100, China. jywang@nwsuaf.edu.cn.
authors.forename: Shaofei
authors.initials: S
authors.lastname: Shen
authors.forename: Chao
authors.initials: C
authors.lastname: Ma
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.forename: Yaolei
authors.initials: Y
authors.lastname: Wang
authors.forename: Jian-Chun
authors.initials: JC
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Xu
authors.forename: Tianbao
authors.initials: T
authors.lastname: Li
authors.forename: Long
authors.initials: L
authors.lastname: Pang
authors.forename: Jinyi
authors.initials: J
authors.lastname: Wang
mesh_terms: D001773:Blood Cells / Q000166:cytology*; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D057446:Hydrodynamics; D020014:K562 Cells; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods