Dresden 2009 – scientific programme

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BP: Fachverband Biologische Physik

BP 10: Biofluiddynamics

BP 10.3: Talk

Tuesday, March 24, 2009, 14:45–15:00, HÜL 186

Defined Spatial and Time Resolved Microfluidics for Stimulation of Chemotactic Cells — •Börn Meier, Delphine Arcizet, Joachim Rädler, and Doris Heinrich — Biophysics of Cell Dynamics Group, Fakultät für Physik und Center for Nanoscience (CeNS), Ludwig-Maximilian-Universität München, Geschwister-Scholl-Platz 1, D-80539 München, Germany

The ability of cells to move into the direction of a chemical gradient is an important mechanism involved in physiological responses, like the movement of neutrophils in tissue or for angiogenesis, the development of new blood vessels. In the model organism Dictyostelium discoideum (Dd) it has been shown that the response to chemotactic stimulation occurs within seconds. Therefore it is important to manipulate the chemoattractant concentration on very short timescales, which is possible with the recent developments in microfluidics.

We have built a microfluidic setup to measure the sub-second chemotactic response of single cells, which allows us to expose the cells to defined gradients of chemoattractant, changing directions with switching times down to a few seconds. Consequently we observed a time-dependent directed motion for Dd cells. To study the local protein response to a fast switching gradient by fluorescence imaging, we use knock-out and fluorescently labelled mutants of Dd cells.

We aim at trapping cells by adjusting the switching times of the chemoattractant gradient in a way that the cells repolarise without an actual displacement. Therefore we will be able to perform high precision measurements on immobilised cells.