Dresden 2006 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 28: Single Molecule Probes
AKB 28.1: Vortrag
Freitag, 31. März 2006, 12:00–12:15, ZEU 255
Optical trapping and tracking: novel approaches in cell biophysics — •Alexander Rohrbach1,2 and Holger Kress2 — 1Institute of Microsystem Technology (IMTEK), University of Freiburg, Georges-Köhler-Allee 102, 79110 Freiburg — 2European Molecular Biology Laboratory (EMBL), Meyerhofstrasse 1, 69117 Heidelberg
Optical micromanipulation has open new possibilities for investigating infrequent events. Especially optical traps allow increasing the interaction probability between interacting partners. Energy fluctuations and diffusion are maintained inside the optical trap, enabling a natural dynamic interaction, which is not given e.g. in AFM experiments. However, only a fast and precise three-dimensional detection system allows measuring the broad spectrum of interaction dynamics. Although holographic traps enable fascinating possibilities of optical manipulation, particle tracking and thus measurements are strongly limited in speed and precision. This drawback can be overcome with e.g. scanning optical traps. In this talk I demonstrate, how fluctuation dominated processes in cell biology can be controlled and measured with nanometer precision and at a rate of 1 kHz to 1 Mhz. On the one hand, the uptake, binding and intracellular transport of particles to/in macrophages are investigated. On the other hand, a complete helical bacterium (a 200 nm thin spiroplasm) is oriented and tracked interferometrically in a scanning optical trap. This allows new insights into the complex flexing and rotation dynamics of this simplest form of life.