We develop and employ a broad portfolio of techniques to measure the biophysical properties of cells. Our optical and mechanical/rheological toolbox includes:
Deformability Cytometry (DC)
DC comprises the measurement of cell deformability by deforming cells in microchannel flow [Urbanska, 2020]. The most prominent example developed in our group is Real-Time Deformability Cytometry (RT-DC). RT-DC enables single-cell mechanical measurements at throughputs up to 1.000 cells/second with real-time analysis. Subsequent advancements include the additions of simultaneous fluorescence measurements, machine-learning-assisted sorting, and
viscoelasticity measurements [Otto 2015, Rosendahl 2018, Nawaz 2022, Reichel 2024].
Optical Diffraction Tomography (ODT)
ODT is a holographic technique to measure the optical phase information in 3D. We use ODT to map the refractive index of biological samples and infer the mass density at sub-micrometer resolution [Kim 2022, Möckel 2024].
Brillouin Microscopy (BM)
BM is an optical technique to quantitively map the mechanical properties inside a material in 3D and in a non-invasive way [Kabakova 2024]. We use BM to measure objects from subcellular compartments up to the scale of living organisms. Our combined BM-ODT setup offers a unique way to measure the mechanical properties of biological samples by simultaneously measuring the Brillouin shift, the refractive index, and the material density [Schlüßler 2022].
Atomic Force Microscopy (AFM)
The workhorse in the cell and tissue mechanics community. We use AFM mainly to measure the mechanical properties of adherent cells and tissue slices [Möllmert 2020, Kolb 2023].
Hydrogel Beads
We use hydrogel beads made from polyacrylamide with controlled sizes in the range of 10-20 µm and controlled stiffness of 0.5-10 kPa as force sensors to calibrate our devices and to measure the forces acting in living tissues [Girardo 2018, Wagner 2019, Träber 2019].
Software
We developed several software packages to accelerate the data analysis for our method toolset. You find an overview of our available packages here.
