Tag: Methods

Chemotaxis enables cells to systematically approach distant targets that emit a diffusible guiding substance. However, the visual observation of an encounter between a cell and a target does not necessarily indicate the presence of a chemotactic approach mechanism, as even a blindly migrating cell ...

Cellular force generation and force transmission are of fundamental importance for numerous biological processes and can be studied with the methods of Traction Force Microscopy (TFM) and Monolayer Stress Microscopy. Traction Force Microscopy and Monolayer Stress Microscopy solve the inverse proble...

Camera traps for motion-triggered or continuous time-lapse recordings are readily available on the market. For demanding applications in ecology and environmental sciences, however, commercial systems often lack flexibility to freely adjust recording time intervals, suffer from mechanical component ...

Magnetic tweezers based on a solenoid with an iron alloy core are widely used to apply large forces (∼100 nN) onto micron-sized (∼5 μm) superparamagnetic particles for mechanical manipulation or microrheological measurements at the cellular and molecular level. The precision of magnetic tweezers, h...

We describe a method for quantifying the contractile forces that tumor spheroids collectively exert on highly nonlinear three-dimensional collagen networks. While three-dimensional traction force microscopy for single cells in a nonlinear matrix is computationally complex due to the variable cell ...

Camera images and video recordings are simple and non-invasive tools to investigate animals in their natural habitat. Quantitative evaluations, however, often require an exact reconstruction of object positions, sizes, and distances in the image. Here, we provide an open source software package to...

1. Long-term photographic recordings of animal populations provide unique insights into ecological and evolutionary processes. However, image acquisition at remote locations under harsh climatic conditions is highly challenging. 2. We present a robust, energetically self-sufficient and remote-contro...

Scientific applications often require an exact reconstruction of object positions and distances from digital images. Therefore, the images need to be corrected for perspective distortions. We present CameraTransform, a python package that performs a perspective image correction whereby the height...

In-vitro engineered cardiac tissue grafts are of growing interest for different applications such as substituting scarred myocardial tissue after infarction or chronic cardiomyopathies, or as a drug testing platform. Several studies have recently reported successful fabrication of microtissues from s...

Automated image based tracking is widely used to investigate collective interactions in a variety of biological systems. Applied to diverse environments, ranging from cell to animal colonies, it provides insight into biological processes like cancer metastasis, immunological response, and social str...

Cell migration through a three-dimensional (3-D) matrix depends strongly on the ability of cells to generate traction forces. To overcome the steric hindrance of the matrix, cells need to generate sufficiently high traction forces but also need to distribute these forces spatially in a migration-pro...

Many cell types in our body, such as fibroblasts, immune cells but also cancer cells, are able to actively migrate and squeeze through the tiny pores and cell layers in our tissue. Similarly, blood cells are passively pushed and squeezed through narrow capillaries. In both cases, the deformability o...

Mechanosensation in many organs (e.g. lungs, heart, gut) is mediated by biosensors (like mechanosensitive ion channels), which convert mechanical stimuli into electrical and/or biochemical signals. To study those pathways, technical devices are needed that apply strain profiles to cells, and ideally...

Human cells can be easily deformed -- they stretch or become squashed under external pressure. The relationship between force and cell deformation changes in diseases such as cancer, lung disease and heart disease, as well as muscle disorders. To gain a better understanding of these diseases it is i...