Regensburg 2022 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 7: Poster 1
BP 7.34: Poster
Montag, 5. September 2022, 18:00–20:00, P1
Scanning small angle x-ray scattering of hydrated, keratin-rich cells — •Boram Yu1, Chiara Cassini1, Sophie-Charlotte August1, Manfred Burghammer2, and Sarah Köster1 — 1Institute for X-Ray Physics, Universität Göttingen, Germany — 2ESRF, Grenoble, France
Intermediate filaments (IFs), one of the three main components of the cytoskeleton, form a network that contributes to cell mechanic. Thus, collecting structural information about IFs in their physiological setting, i.e., in whole cells, is crucial. We use scanning small angle x-ray scattering(SAXS) to obtain this information, as it offers both real space overview images with moderate resolution and reciprocal space information with high resolution. X-ray imaging of cells in aqueous state is challenging as their electron density contrast is low. Additionally, the aqueous environment contributes to extremely rapidly spreading radiation damage. For this reason, a fast-scanning mode is employed by moving the sample continuously through the beam rather than step by step, resulting in a significant reduction in exposure time, thus diminishing the radiation damage. As a benchmark for ordered intracellular structures, we investigate mammalian cells expressing the IF protein keratin. A purpose-built chamber maintains the cells hydrated while minimizing the volume of the liquid in the optical path. Despite weak contrast and short exposure times, we are able to retrieve the local main orientation of subcellular structures, thus demonstrating how scanning SAXS offers valuable information from hydrated cells.