The analysis of potentially harmful biological particles is imperative for the mitigation of disease. As a result, there is a growing need for tools which can characterize, detect, and separate biological particles for the alleviation of a multitude of disease. One powerful technique for the analysis of cells is the use of dielectrophoresis (DEP) forces for the manipulation of particle movement. DEP is a particle transport phenomenon, induced by the presence of non-uniform electric fields. The dependence on intrinsic electrical properties of cells, have enabled DEP force to be utilized for numerous biological analyses. This thesis presents the investigation of breast cancer, pathogen, neuronal and glial cells and their DEP profiles. The drug response of various breast cancer cell lines when exposed to a variety of chemical stimuli were analyzed using shifts in their DEP profiles in relation to control groups. These results were supplemented with gene expression analysis to identify biophysical changes which could contribute to the DEP shifts. Additional experiments were conducted for the monitoring of pathogens. Live/dead bacteria mixtures were evaluated using an integrated system with DEP enrichment and impedance spectroscopy. Another application of DEP which was investigated was the separation of heterogeneous mixtures. Through the use of a novel microfluidic channel design, the separation of simulated circulating tumor cells (CTCs) from diluted blood and neuron cells from glial cells was demonstrated. The wide range of applications examined in this thesis highlights the versatility of DEP and the flexibility of the reported devices. / MS / Microscale technology can be utilized for the identification, characterization and sorting of biological material in a plethora of biomedical applications. One promising technique which is capable of cell manipulation is dielectrophoresis (DEP). DEP is a microscale force which causes particles to be attracted or repelled by specific geometries in microchannels. The DEP force is produced by the application of electric fields and can be utilized to analysis biological cell populations. This is because biological particles have unique electrical properties based on their cell morphology. Distinctions in their external protrusions and internal structures contribute to their electrical properties and can be identified in their DEP profiles. Based on this concept a variety of biomedical applications of DEP was explored. Chapter 2 and 3 describe the investigation of cells when exposed to various drugs. Drug induced responses were characterized based on their shifts in their DEP profiles. Chapter 4 presents the a rapid and low-cost live/dead assay for bacteria in aqueous samples through DEP and impedance spectroscopy. In chapter 5, the development of a DEP platform for cell sorting is reported. The wide range of biomedical applications which were explored demonstrate the useful nature of the DEP phenomenon.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/96587 |
| Date | 03 August 2018 |
| Creators | Kikkeri, Kruthika |
| Contributors | Electrical Engineering, Agah, Masoud, Jia, Xiaoting, Baumann, William T. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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