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BP: Fachverband Biologische Physik

BP 26: Poster Session II

BP 26.31: Poster

Donnerstag, 29. März 2007, 17:00–19:30, Poster B

Simultaneous Manipulation and Detection of Cell Membrane Dynamics with High Spatial and Temporal Resolution — •Michael Gögler, Timo Betz, and Josef Käs — Soft Matter Physics, Universität Leipzig, Linnéstrasse 5, 04103 Leipzig, Germany

Cell motility is a fundamental process of many phenomena in nature, such as immune response, morphogenesis, and wound healing. In these events, protrusion of the cell membrane at the leading edge is the fundamental step. We use a new laser based technique to study the membrane motion at the leading edge of a cell with high spatial and temporal resolution in the nanometer and microseconds range, respectively. A diffraction limited laser spot is positioned at the leading edge of a cell and the forward scattered light is imaged on a quadrant diode detector which serves as a position sensitive device. We investigated the membrane motion at the leading edge of different cell types, such as fish keratocytes and red blood cells (RBC). We show that this technique can be used to locally manipulate the leading edge of a cell and to detect the movement of the leading edge simultaneously. By increasing the laser intensity we were able to exert a significant force (several pN) on the RBC's leading edge that is strong enough to deform the cell and to change its membrane dynamics. For RBCs it was possible to determine the membrane stiffness and shear modulus. Further capabilities of this technique such as cell imaging are presented.