Phase-Sensitive Probe-Free Active Microrheology in Living Cells

• Applicant: Professor Dr. Moritz Kreysing
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Biophysics
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515462906

‘Rheology’ (Greek) studies the science of flows. Practically, rheological properties of materials are determined using external force as proxy, acting on their interfaces as a perturbative stimulus. This is easily done with bulk materials (water, glycerol etc.), but has some limitations where mechanical access is difficult. This is especially true for cells and developing embryos, whose structure, function, physiological and diseased state, or developmental potential are thought to be interlinked with their cytoplasmic rheology. Here we propose to advance the use of optically generated thermoviscous flows as a probe-free way to measure rheology in living cells, in particular gelation behaviour, for which we extend previous measurements of oscillatory amplitudes into the time domain. This work will enable us to quantify material properties of cells and their constituents via interactive microscopy, opening the door to exploiting subcellular rheology as a powerful predictor of changes in cell physiology and disease-development.

• DFG Programme: Research Grants