Cell separation using tilted-angle standing surface acoustic waves
- 25 August 2014
- journal article
- research article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 111 (36), 12992-12997
- https://doi.org/10.1073/pnas.1413325111
Abstract
Separation of cells is a critical process for studying cell properties, disease diagnostics, and therapeutics. Cell sorting by acoustic waves offers a means to separate cells on the basis of their size and physical properties in a label-free, contactless, and biocompatible manner. The separation sensitivity and efficiency of currently available acoustic-based approaches, however, are limited, thereby restricting their widespread application in research and health diagnostics. In this work, we introduce a unique configuration of tilted-angle standing surface acoustic waves (taSSAW), which are oriented at an optimally designed inclination to the flow direction in the microfluidic channel. We demonstrate that this design significantly improves the efficiency and sensitivity of acoustic separation techniques. To optimize our device design, we carried out systematic simulations of cell trajectories, matching closely with experimental results. Using numerically optimized design of taSSAW, we successfully separated 2- and 10-µm-diameter polystyrene beads with a separation efficiency of ∼99%, and separated 7.3- and 9.9-µm-polystyrene beads with an efficiency of ∼97%. We illustrate that taSSAW is capable of effectively separating particles–cells of approximately the same size and density but different compressibility. Finally, we demonstrate the effectiveness of the present technique for biological–biomedical applications by sorting MCF-7 human breast cancer cells from nonmalignant leukocytes, while preserving the integrity of the separated cells. The method introduced here thus offers a unique route for separating circulating tumor cells, and for label-free cell separation with potential applications in biological research, disease diagnostics, and clinical practice.Keywords
This publication has 33 references indexed in Scilit:
- Electric impedance microflow cytometry for characterization of cell disease statesLab on a Chip, 2013
- Spiral microchannel with rectangular and trapezoidal cross-sections for size based particle separationScientific Reports, 2013
- On-chip manipulation of single microparticles, cells, and organisms using surface acoustic wavesProceedings of the National Academy of Sciences of the United States of America, 2012
- Separation of platelets from whole blood using standing surface acoustic waves in a microchannelLab on a Chip, 2011
- Clinical microfluidics for neutrophil genomics and proteomicsNature Medicine, 2010
- Label-free cell separation and sorting in microfluidic systemsAnalytical and Bioanalytical Chemistry, 2010
- Isolation of rare circulating tumour cells in cancer patients by microchip technologyNature, 2007
- Continuous inertial focusing, ordering, and separation of particles in microchannelsProceedings of the National Academy of Sciences of the United States of America, 2007
- Biomechanics and biophysics of cancer cellsActa Biomaterialia, 2007
- Deterministic hydrodynamics: Taking blood apartProceedings of the National Academy of Sciences of the United States of America, 2006