Hunter Danesi
BME MS Thesis Defense Presentation
Date: 2026-03-31
Time: 2:30 PM - 4:00 PM
Location / Meeting Link: Krone Engineering Biosystems Building

Committee Members:
Dr. Rafael Davalos, Dr. David Myers, Dr. Erin Henslee

Title: Dielectrophoretic Separation of Early Apoptotic and Live THP-1 Cells Based on Distinct Electrical Phenotype

Abstract:
Dielectrophoresis (DEP) is a label-free technique that enables cell manipulation based on intrinsic electrical properties and has been widely used for cell characterization and separation. In the context of single-cell genomics, maintaining high cell viability is critical, as the inclusion of apoptotic or compromised cells can negatively affect downstream analysis. While prior studies have demonstrated the ability of DEP to separate live and dead cells, limited work has investigated whether cells can be distinguished during early-stage apoptosis, before complete cell death occurs. The purpose of this study is to determine whether early-stage apoptotic THP-1 cells can be differentiated from live THP-1 cells using contactless dielectrophoresis (cDEP) based on differences in electrical phenotype. Previous approaches have primarily focused on fully apoptotic or dead cells, and have not explored separation at earlier stages where cellular changes are more subtle. This represents a gap in the ability to improve cell viability prior to single-cell analysis.To address this question, apoptosis was induced in THP-1 cells through electroporation, and apoptotic progression was validated using a Caspase 3/7 activity assay. Cells were then introduced into a microfluidic cDEP platform and analyzed across a range of applied frequencies and voltages. Trapping behavior was quantified through video-based image analysis, allowing for comparison between live, apoptotic, and mixed cell populations.Results demonstrated frequency-dependent differences in dielectrophoretic trapping behavior between populations. At lower frequencies, apoptotic cells exhibited increased trapping relative to live cells, while at higher frequencies, particularly 700 kHz and 800 kHz, apoptotic cells showed reduced trapping compared to live cells with statistically significant differences. Voltage-dependent trends were consistent across populations, with apoptotic cells requiring higher voltages to achieve comparable trapping. These findings indicate that early-stage apoptotic THP-1 cells exhibit distinct electrical phenotypes that can be identified using cDEP. This work establishes a label-free method for distinguishing apoptotic from live cells prior to full cell death, with implications for improving cell viability in single-cell genomics workflows.