Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

BP: Fachverband Biologische Physik

BP 34: Imaging

BP 34.2: Vortrag

Donnerstag, 3. April 2014, 09:45–10:00, ZEU 250

3D-Density Measurements of the Bacterium Deinococcus Radiodurans by Tomo-Ptychographic X-ray Imaging — •Robin N. Wilke¹, Marius Priebe¹, Matthias Bartels¹, Klaus Giewekemeyer², Ana Diaz³, Malte Vassholz¹, and Tim Salditt¹ — ¹Institut für Röntgenphysik, Universität Göttingen, Germany — ²European XFEL, Hamurg, Germany — ³Paul Scherrer Institut, Villigen, Switzerland

D.radiodurans[1,2] is famous for its extraordinary resistance to high doses of ionizing radiation, which has been tentatively linked to the structural organization of DNA in the nucleoid[3,4]. Determination of the mesoscopic density in the nucleoid would help to test these ideas and eventually to discriminate different models of DNA packing.

Ptychographic phasing[5-9] is one promising (coherent) X-ray imaging technique for this particular problem and other biological applications. We present results of quantitative 3D resolved mass density maps of D.radiodurans by a combination of ptychography and tomography of unstained, unsliced and freeze-dried bacterial cells[8]. In addition, we show how ptychographic results can be enhanced by increasing the dynamic range of pixel detectors by introducing a Semi-Transparent Central Stop[9].

[1]Levin-Zaidman et al.,Science299,2003

[2]Eltsov&Dubochet,J.Bacteriol.187,2005

[3]Eltsov&Dubochet,J.Bacteriol.188,2006

[4]Minsky et al.,J.Bacteriol.188, 2006

[5]Rodenburg et al.,PRL98,2007.

[6]Thibault et al.,Science321,2008

[7]Giewekemeyer et al.,PNAS107,2010

[8]Wilke et al.,Opt.Expr.20,2012

[9]Wilke et. al.,ActaCryst.A69,2013