Dielectric characterization of Babesia bovis using the dielectrophoretic crossover frequency

Authors: OLADOKUN, RAPAEL - West Virginia University; ADEKANMBI, EZEKIEL - Intel - Chandler Campus; Ueti, Massaro; SRIVASTAVA, SOUMYA - West Virginia University

Submitted to: Electrophoresis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/19/2023
Publication Date: 5/9/2023
Citation: Oladokun, R., Adekanmbi, E., Ueti, M.W., Srivastava, S. 2023. Dielectric characterization of Babesia bovis using the dielectrophoretic crossover frequency. Electrophoresis. 44(11-12):988-1001. https://doi.org/10.1002/elps.202200263.
DOI: https://doi.org/10.1002/elps.202200263

Interpretive Summary: The transmission of Babesia parasites by blood transfusion often results in high morbidity and mortality in recipients. We developed an electrokinetic technique on a microfluidic platform to improve the diagnostics of Babesia spp. The difference in the dielectric properties of Babesia spp. infected erythrocytes vs. healthy erythrocytes were exploited to design a fast and cost-effective diagnostic tool. One crucial factor for a successful diagnostic platform via dielectrophoretic separation is the dielectric characterization of Babesia infected erythrocytes, which is investigated in this paper. The influence of medium conductivity and erythrocytes phenotype and genotype over the first crossover frequency are used to quantify the dielectric properties of the infected cells. A sigmoidal curve was plotted via curve fitting of the single-shell model, which has been proven appropriate for parasitized cell populations where considerable cell geometry variation occurs. The difference in these curves is relevant for the separation of cells population. Microliters of sample and reagent were used throughout this experiment; the scale, results obtained, and simplicity of the system often makes it very suitable for point-of-care babesiosis disease diagnostics.

Technical Abstract: Coinfection with the tick-transmitted pathogen Babesia spp. is becoming a serious health problem because of the erythrocyte invasion through Ixodes scapularis tick. The transmission of this protozoan by blood transfusion often results in high morbidity and mortality in recipients. A novel way to detect parasitized erythrocytes is by utilizing dielectrophoresis, an electrokinetic technique on a microfluidic platform to improve the diagnostics of Babesia spp. The difference in the dielectric properties of Babesia spp. infected erythrocytes vs. healthy erythrocytes were exploited to design a fast and cost-effective diagnostic tool. One crucial factor for a successful diagnostic platform via dielectrophoretic separation is the dielectric characterization of Babesiainfected erythrocytes, which is investigated in this paper. The influence of medium conductivity and erythrocytes phenotype and genotype over the first crossover frequency (fco1) are used to quantify the dielectric properties of the infected cells. A sigmoidal curve was plotted via curve fitting of the single-shell model, which has been proven appropriate for parasitized cell populations where considerable cell geometry variation occurs. The difference in these curves is relevant for the separation of cells population. Microliters of sample and reagent were used throughout this experiment; the scale, results obtained, and simplicity of the system often makes it very suitable for point-of-care babesiosis disease diagnostics.