Berlin 2024 – scientific programme
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BP: Fachverband Biologische Physik
BP 14: Poster IIa
BP 14.1: Poster
Tuesday, March 19, 2024, 18:00–20:30, Poster E
Microfluidic Separation of Viable and Non-viable Legionella Cells by a Quantifiable Dielectrophoresis Approach — •Madeline Altmann1, Anders Henriksson1, Peter Neubauer1, and Mario Birkholz2 — 1Laboratory of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, Ackerstr. 76, ACK24, D-13355 Berlin, Germany — 2IHP Leibniz-Institut für Innovative Mikroelektronik, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany
Traditional pathogen detection methods, notably PCR, often fail to distinguish viable and non-viable cells. This distinction is crucial as non-viable cells hold limited pathogenic potential. To overcome this limitation, analytical methods must be able to separate between viable from non-viable cells. Dielectrophoresis (DEP) can non-invasively separate cells according to viability, allowing for increased accuracy in subsequent bioanalytic workflows. This study focuses on employing positive dielectrophoresis in a microfluidic system to separate viable Legionella parisiensis cells from non-viable cells rendered inactive via heat shock to refine the specificity of biosensors. Although separation in realistic inactivation conditions was difficult, discrimination of viable cells was achieved by a video-based, quantifiable DEP method, that evaluates the percentage of fluorescent cells in a region of interest around the electrodes. It was found that long heat shock inactivation times decrease the positive DEP-effect at higher frequencies, enabling a separation of viable Legionella above 25 MHz and 10 Vpp in both tap water and demineralized water.
Keywords: Dielectrophoresis; Cell Separation; Legionella; Microfluidics