SKM 2023 – scientific programme

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BP: Fachverband Biologische Physik

BP 29: Statistical Physics of Biological Systems II (joint session BP/DY)

BP 29.6: Talk

Friday, March 31, 2023, 11:00–11:15, BAR Schö

Microrheology of red blood cell cytosol — •Thomas John and Christian Wagner — Universität des Saarlandes, Saarbrücken

Tracking of small particles undergoing a Brownian motion is a widespread method in passive microrheology. Washed human red blood cells (RBC) are destroyed by ultrasound treatment to extract the cytosol, the hemoglobin and protein solution inside the cells. We use microrheology with sub-micrometer-sized particles to determine the viscosity of the cytosol. Since the cytosol is always diluted with an unknown amount of water due to the treatment, this small dilution has a huge impact on the viscosity. To circumvent this problem, we measured very accurately the mass density of every sample. However, the resulting density-viscosity relation is a strong monotonic increasing relation. In a separate experiment we determined the mass density distribution of individual intact RBCs in a continuous density gradient by centrifugation. Finally, we can present the probability density distribution of the viscosity in naturally distributed human RBCs.