Cryo 3D X-ray imaging of the cell

March 23-24, 2015

In structural cell biology detailed structural and functional descriptions of the different cellular components must be correlated with a topological map of these components at the whole cellular level. Cryo-electron tomography has proven to be a suitable tool in this context with resolutions on the order of a few nanometers [1]. However, the intrinsic sample-thickness limitation of cryo-electron tomography forces either data collection through the thinnest part of the cell or necessitates sectioning the cell into very fine slices. These multiple serial sections then have to be aligned in a process which is exceedingly time consuming in order to reconstruct the 3D information of the whole cell volume [2]. In addition, the correlation of information with optical microscopy has become an important technique used to study biological events at different levels. However the gap between these two microscopy techniques in terms of magnification, thickness and resolution has complicated the microscopy information gateway. Cryo 3D X-ray imaging is a new complementary approach in this field that can provide information at 50 nm 3D resolution of the organelle organization in whole, unstained, un-sectioned cells [3, 4, 5, 6, 7]. Supplementary to the structural information, trace elemental analysis of cells and tissues can also be achieved in 2D and 3D [8]. Several beamlines at different synchrotrons in Europe (ALBA in Spain, Diamond in UK, HZB-BESSY II and Petra III in Germany and Soleil in France) are providing or will soon provide access for biologists to cryo X-ray nanotomography using absorption, phase and fluorescence signals. This satellite workshop aims at making these techniques known to a broader biological community by presenting both the latest studies on key biological questions and promoting fruitful discussions among participants.

The Monday morning and at least some of the afternoon session will be devoted to topics such as instrumentation advances, phase contrast implementation in X-ray microscopy, correlative cryo light and X-ray microscopy implementation, analysis tools for both reconstruction and segmentation of X-ray microscopy images within the Biostruct-X JRA workpackage WP8 (3D Tomographic X-ray Imaging of Biological Cells).

The latter part of the afternoon session might also include some talks on X-ray microscopy applications in biology, but these will not be invited speakers, and so will depend on who from the X-ray microscopy and/or cell biology community decides to attend the meeting.

The Tuesday half-day session will be held as a satellite workshop of the International German Society for Cell Biology meeting in Cologne that will take place from March 24 to March 27 2015 at the University of Cologne.The satellite workshop is designed to introduce cell biologists to X-ray microscopy, and will also include several other high resolution microscopy approaches.

[1] K. Grunewald and M. Cyrklaff, Curr Opin Microbiol, 9, 437-442 (2006).
[2] A.B. Noske et al. J. Struct. Biol. 161, 298–313 (2008).
[3] J.L. Carrascosa et al. J. Struct. Biol. 168, 234-239 (2009).
[4] G. Schneider et al. Nat. Methods 7, 985-987 (2010).
[5] F.J. Chichón et al., J. Struct. Biol. 177, 202-211 (2012).
[6] S. Kapishnikov et al. PNAS 109, no.28, 11188-11193 (2012).
[7] E.M.H. Duke et al., Ultramicroscopy 143 (2014), 77-87
[8] Ye Yuan et al, ACS Nano 7, 10502–10517 (2013).