Applicability of bulk and single-cell electrical impedance spectroscopy for bioprocess monitoring
| dc.contributor.author | Absalan, Sara | |
| dc.contributor.examiningcommittee | Bridges, Gregory (Electrical and Computer Engineering) | |
| dc.contributor.examiningcommittee | Butler, Michael (Microbiology) | |
| dc.contributor.supervisor | Salimi, Elham | |
| dc.date.accessioned | 2024-01-03T17:26:24Z | |
| dc.date.available | 2024-01-03T17:26:24Z | |
| dc.date.issued | 2023-12-26 | |
| dc.date.submitted | 2023-12-26T23:15:56Z | en_US |
| dc.degree.discipline | Electrical and Computer Engineering | en_US |
| dc.degree.level | Master of Science (M.Sc.) | |
| dc.description.abstract | The dielectric properties of biological cells serve as indicators of their physiological state. Electrical Impedance Spectroscopy (EIS) is a highly effective, non-invasive and label-free technique that can be utilized to infer information about the physiological condition of biological cells by measuring their electrical impedance across a frequency range. This technique can effectively distinguish between various types of cells and provide critical insights into their respective states, whether as individual cells or as a suspension of cells. In this thesis, the applicability of bulk and single-cell EIS for bioprocess monitoring was investigated. We developed a theoretical framework to assess the sensitivity of bulk and single-cell EIS to the cell and culture parameters of Chinese Hamster Ovary (CHO) cells (such as cell density in the culture, culture viability, cell size, and cell dielectric properties) and correlated the sensitivity analysis outcomes with the results obtained from experimental measurements. For bulk EIS measurements, we performed a comprehensive sensitivity analysis to identify the cell and culture parameters that significantly influence the permittivity spectrum measured by bulk EIS probes. For our analysis, we utilized a two-population dielectric model, including both viable and non-viable cells, to accurately represent the cell culture within a bioreactor. Additionally, we considered a double-shell dielectric model, comprising two concentric shelled spheres, to account for the nucleoplasm, nuclear envelope, cytoplasm, and plasma membrane of CHO cells. We then compared the results of our sensitivity analysis with experimental data obtained by measuring CHO cells in a lab-scale bioreactor, employing commercial bulk electrical impedance spectroscopy probes. We concluded that the most reliable cell or culture parameter that bulk EIS probes can assess is the viable cell density, through low-frequency measurements. In conventional bulk assays that rely on average properties of cell suspensions, the critical information from individual cells is lost. Consequently, researchers have increasingly turned to single-cell analysis to better understand the actual morphological and physiological properties of individual cells. By incorporating EIS measurement into microfluidic devices, highly sensitive EIS systems have been developed which are capable of single-cell analysis. Such microfluidic-based EIS systems measure the frequency-dependent complex impedance of single cells as they pass through a microfluidic channel with embedded sets of electrodes. We analyzed the sensitivity of single-cell EIS to cell dielectric properties to identify the key parameters that impact the measured impedance of an individual cell. We concluded that viable and non-viable CHO cells can be discriminated based on the phase of sensitivity of the measured impedance at frequencies above 10 MHz. This was verified with the experimental results measured from single CHO cells under starvation conditions over the frequency range from 0.3 to 30 MHz. | |
| dc.description.note | February 2024 | |
| dc.identifier.uri | http://hdl.handle.net/1993/37895 | |
| dc.language.iso | eng | |
| dc.rights | open access | en_US |
| dc.subject | Electrical Impedance Spectroscopy, Single cell analysis, CHO cells, Bulk Impedance Spectroscopy | |
| dc.title | Applicability of bulk and single-cell electrical impedance spectroscopy for bioprocess monitoring | |
| dc.type | master thesis | en_US |
| local.subject.manitoba | no | |
| oaire.awardTitle | University of Manitoba Graduate Fellowship | |
| project.funder.identifier | https://doi.org/10.13039/100010318 | |
| project.funder.name | University of Manitoba |