Enhancing size based size separation through vertical focus microfluidics using secondary flow in a ridged microchannel

• Type of Material: Article
• Authors: Bushra Tasadduq, Georgia Institute of Technology; Wilbur Lam, Emory University; Alexander Alexeev, Georgia Institute of Technology; A. Faith Sarioglu, Georgia Institute of Technology; Todd Sulchek, Georgia Institute of Technology
• Language: English
• Date: 2017-12-12
• Publisher: Nature Research (part of Springer Nature): Fully open access journals
• Publication Version: Final Published Version
• Copyright Statement: © 2017 The Author(s).
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1038/s41598-017-17388-w
• Title of Journal or Parent Work: Scientific Reports
• ISSN: 2045-2322
• Volume: 7
• Issue: 1
• Start Page: 17375
• End Page: 17375
• Grant/Funding Information: This research was supported by NSF project number CBET-0932510, National Institute of Health (1R21EB020977-01), the Center for Pediatric Nanomedicine Seed Grant, the Fulbright Scholarship Program, and the President’s Undergraduate Research Award (PURA) program at Georgia Tech.
• Keywords: FILTRATION; LEUKAPHERESIS; PARTICLES; Science & Technology - Other Topics; DEVICE; FRACTIONATION; Multidisciplinary Sciences; CAPTURE; Science & Technology; CELL-SEPARATION; MICROPARTICLES
• Research Categories: Biology, Cell

Abstract

High throughput size based separation and sorting of bioparticles and cells is critical to a variety of biomedical processing steps for medical diagnostics and pharmaceutical purification. Improving microfluidic size-based particle/cell sorting is a challenge to better address the need for generating more homogeneous subpopulations for study and use. We propose a novel advance to microfluidic sorting devices that uses three-dimensional focusing of the sample to optimally position particles to amplify the size-dependent differences in trajectories caused by differential secondary flows. The result is an increase in the purity of small particles by 35- fold and large particles by 8-fold in comparison to unfocused flow. Our simulated and experimental data reveal for the first time that positioning particles in three-dimensional space can be used to better leverage the differential lateral movement of particles with different sizes as they flow in microchannel with transverse secondary flows. The focusing approach may also be useful to improve positioning of particles with inertial channels with multiple equilibrium positions. This technique performs continuous-flow, high throughput size based sorting of millions of particles and cells in a minute without any pre and post-processing. We have also demonstrated improved enrichment and recovery of white blood cells from human blood.