Regensburg 2025 – scientific programme

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BP: Fachverband Biologische Physik

BP 17: Poster Session II

BP 17.37: Poster

Tuesday, March 18, 2025, 18:00–20:30, P4

A fast and quantitative method to study the membrane tension of suspended cells — •Eric Sündermann, Bob Fregin, Doreen Biedenweg, and Oliver Otto — Institute of Physics, University of Greifswald, Greifswald, Germany

The development of high-throughput methods for cell mechanical research is becoming increasingly important as the analysis of large samples improves the statistical robustness to identify rare cell populations and transfer results from basic science into clinical applications. Various techniques are available for bulk mechanics, but none can analyse membrane tension with the throughput of a flow cytometer.
Here, we present membrane tension cytometry (MTC), that uses Flipper-TR, a fluorescent dye with a fluorescence lifetime being proportional to the tension inside a lipid bilayer. First, we established a calibration procedure using osmotically-stressed red blood cells. Next, we move to HL60 cells, a myeloid precursor cell line, which we exposed to various chemical and mechanical stresses. We find an increased fluorescence lifetime for increasing hydrodynamic stresses, as expected. Finally, we used methyl-β-cyclodextrin and Cytochalasin D to disturb cholesterol and filamentous actin levels, respectively. Our results show, that MTC is sensitive to membrane changes while being insensitive to cytoskeletal alterations.

Keywords: Fluorescence lifetime; Deformability cytometry; Membrane tension; Membrane mechanics; red blood cells