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- All Subjects: Dielectrophoresis
- Creators: Buttry, Daniel A
- Creators: Davis, Paige Elizabeth
Description
Microfluidics has shown great potential in rapid isolation, sorting, and concentration of bioparticles upon its discovery. Over the past decades, significant improvements have been made in device fabrication techniques and microfluidic methodologies. As a result, considerable microfluidic-based isolation and concentration techniques have been developed, particularly for rapid pathogen detection. Among all microfluidic techniques, dielectrophoresis (DEP) is one of the most effective and efficient techniques to quickly isolate and separate polarizable particles under inhomogeneous electric field. To date, extensive studies have demonstrated that DEP devices are able to precisely manipulate cells ranging from over 10 μm (mammalian cells) down to about 1 μm (small bacteria). However, very limited DEP studies on manipulating submicron bioparticles, such as viruses, have been reported.
In this dissertation, rapid capture and concentration of two different and representative types of virus particles (Sindbis virus and bacteriophage M13) with gradient insulator-based DEP (g-iDEP) has been demonstrated. Sindbis virus has a near-spherical shape with a diameter ~68 nm, while bacteriophage M13 has a filamentous shape with a length ~900 nm and a diameter ~6 nm. Under specific g-iDEP experimental conditions, the concentration of Sindbis virus can be increased two to six times within only a few seconds, using easily accessible voltages as low as 70 V. A similar phenomenon is also observed with bacteriophage M13. Meanwhile, their different DEP behavior predicts the potential of separating viruses with carefully designed microchannels and choices of experimental condition.
DEP-based microfluidics also shows great potential in manipulating blood samples, specifically rapid separations of blood cells and proteins. To investigate the ability of g-iDEP device in blood sample manipulation, some proofs of principle work was accomplished including separating two cardiac disease-related proteins (myoglobin and heart-type fatty acid binding protein) and red blood cells (RBCs). Consistent separation was observed, showing retention of RBCs and passage of the two spiked protein biomarkers. The numerical concentration of RBCs was reduced (~70 percent after one minute) with the purified proteins available for detection or further processing. This study explores and extends the use of the device from differentiating similar particles to acting as a sample pretreatment step.
In this dissertation, rapid capture and concentration of two different and representative types of virus particles (Sindbis virus and bacteriophage M13) with gradient insulator-based DEP (g-iDEP) has been demonstrated. Sindbis virus has a near-spherical shape with a diameter ~68 nm, while bacteriophage M13 has a filamentous shape with a length ~900 nm and a diameter ~6 nm. Under specific g-iDEP experimental conditions, the concentration of Sindbis virus can be increased two to six times within only a few seconds, using easily accessible voltages as low as 70 V. A similar phenomenon is also observed with bacteriophage M13. Meanwhile, their different DEP behavior predicts the potential of separating viruses with carefully designed microchannels and choices of experimental condition.
DEP-based microfluidics also shows great potential in manipulating blood samples, specifically rapid separations of blood cells and proteins. To investigate the ability of g-iDEP device in blood sample manipulation, some proofs of principle work was accomplished including separating two cardiac disease-related proteins (myoglobin and heart-type fatty acid binding protein) and red blood cells (RBCs). Consistent separation was observed, showing retention of RBCs and passage of the two spiked protein biomarkers. The numerical concentration of RBCs was reduced (~70 percent after one minute) with the purified proteins available for detection or further processing. This study explores and extends the use of the device from differentiating similar particles to acting as a sample pretreatment step.
ContributorsDing, Jie (Author) / Hayes, Mark A. (Thesis advisor) / Ros, Alexandra (Committee member) / Buttry, Daniel A (Committee member) / Arizona State University (Publisher)
Created2017
Description
Bacteria play a vital role in the world ecosystem, more importantly human health and disease. The capability to differentiate and identify these microorganisms serves as an important research objective. In past years, separations-based approaches have served as a way to observe and identify bacteria based on their characteristics. Gradient insulator dielectrophoresis (g-iDEP) provides benefits in identifying serotypes of a single species with precise separation. Separation of Staphylococcus epidermidis in a single g-iDEP microchannel is conducted exploiting their electrophoretic and electrokinetic properties. The cells were captured and concentrated at gates with interacting forces within the microchannel to clearly distinguish between the two strains. These results provide support for g-iDEP serving as a separating method and, furthermore, future clinical applications.
ContributorsDavis, Paige Elizabeth (Author) / Hayes, Mark (Thesis director) / Borges, Chad (Committee member) / Jones, Paul (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor)
Created2015-05