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BP: Fachverband Biologische Physik
BP 13: Imaging
BP 13.8: Talk
Tuesday, March 12, 2013, 11:30–11:45, H44
Observing lipid diffusion in membranes with microsecond time and nanometer spatial resolution — •Susann Spindler1, Chia-Lung Hsieh2, Jens Ehrig1, and Vahid Sandoghdar1 — 1MPI for the science of light, Erlangen, Germany — 2Institute of Atomic and Molecular Sciences, Academia Sinica, Taiwan
Lipid membranes play an important role in biological cells not only by defining the boundaries of the cell and cell organelles, but also by taking an active part in membrane trafficking and signaling. Remarkably, while a great deal is known about lipid membranes, a large number of fundamental questions remains open. These are for example issues concerning the local nanoscopic heterogeneity of the membrane induced via lipid–lipid and lipid–protein interactions. While this nano-organisation is believed to be crucial for the high functionality of the cell membrane, it is still far from being well understood. To address this issue, a high spatial and temporal resolution is needed.
In our laboratory, we have developed a powerful approach for single-particle-tracking based on interferometric scattering (iSCAT) microscopy, which meets these requirements. By attaching small gold nanoparticles of 20 nm diameter to lipid molecules and detecting their weak linear scattering signal by iSCAT, we are able to localize the position of the molecules with nanometer-accuracy within microseconds. This allows us to detect even very small deviations from free diffusion, opening the door to studying membrane dynamics with unprecedented clarity. We will present experimental data for a variety of systematic studies.