Thesis
Separation of circulating tumor cells from blood using DLD and DEP manipulation
Washington State University
Master of Science (MS), Washington State University
05/2021
DOI:
https://doi.org/10.7273/000004272
Handle:
https://hdl.handle.net/2376/125363
Abstract
Circulating Tumor Cells (CTCs) play a prominent role in early cancer detection. Emerging Label-free techniques can be promising to CTC detection due to advantages in preserving cell integrity and minimal sample consumption. Deterministic Lateral Displacement (DLD) is a size-based label-free technique employing laminar flow for continuous sorting of suspended cells. However, separation based solely on size is challenging as the size distributions of CTCs tend to overlap with blood cells. Moreover, the rarity of CTCs in blood requires high throughput processing of samples for clinical utility. In this thesis, a dielectrophoretic DLD technique is presented to segregate CTCs from blood. This technique utilizes the cell size and dielectric properties as well as particle movement caused by polarization effect to accomplish continuous separation at high flow rates. A numerical model is developed and validated to investigate the effects of various parameters related to the fluid flow, micro-post array, and electric field. It is demonstrated that the dielectrophoretic DLD with specific post arrangement can continuously separate A549 lung CTCs from WBCs by applying a field frequency close to the crossover frequency of CTCs. In the second part of this thesis, asymmetrical gap sizes are proposed for DLD devices to improve their throughput and separation resolution. In fact, for a successful separation in sub-micron regime, the gap sizes of DLD devices need to be decreased which drastically enhances the device hydraulic resistance leading to a remarkable reduction in throughput. Our numerical results show that asymmetrical gap sizes by varying vertical and horizontal gaps enables us to achieve effective particle separation without a significant drop in throughput. This procedure may reduce the fabrication difficulties of DLD posts and improve the throughput and the resolution of DLD critical diameter resulting in separation of smaller particles. It is demonstrated that although high Reynolds regime increases DLD hydraulic resistance, it can improve DLD throughput because its effect on the hydraulic resistance is negligible compared to the effect of asymmetric gap size. Furthermore, a modified equation is derived based on the simulated results to estimate the critical diameter of such devices with design parameters.
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Details
- Title
- Separation of circulating tumor cells from blood using DLD and DEP manipulation
- Creators
- Mehdi Rahmati
- Contributors
- Xiaolin Chen (Advisor) - Washington State University, Engineering and Computer Science (VANC), School of
- Awarding Institution
- Washington State University
- Academic Unit
- Engineering and Computer Science (VANC), School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900896414101842
- Language
- English
- Resource Type
- Thesis