The current equipment comprises several dedicated cryo-transmission electron microscopes (see spreadsheet) which are used either for cellular cryo-electron tomography, single particle investigations or both. All microscopes are manufactured by FEI Company, Eindhoven, The Netherlands (former Philips) and all are equipped with digital cameras (CCDs) of different sizes (respectively detection area and pixelsize). All microsopes operate at liquid nitrogen temperature (90K) and the Polara instruments can be even cooled down to liquid helium temperature (10K).
|Name of instrument||Vintage||Operation voltage [kV]||Energy filter||CCD||Applications|
|CM 120 Biofilter||1993||120||GIF1100||Gatan 1024x1024 (24 µm) postGIF||Cellular tomography|
|CM 200 FEG||1991||160/200||TVIPS 4096x4096 (15 µm)||Single particle|
|Tecnai F20||2007||120/160/200||FEI Eagle 4096x4096 (15 µm)||Single particle|
|Tecnai 'Polara' G2 F30 (1)||2003||300||HR-GIF||Gatan 4096x4096 (15 µm) preGIF
Gatan 2048x2048 (30 µm) postGIF
|Tecnai 'Polara' G2 F30 (2)||2008||300||GIF 2000||Gatan 2048x2048 (30 µm) postGIF||Cellular tomography|
|Titan KRIOS (1)||2007||80-300||TVIPS 8192x8192 (15 µm)||Single particle|
|Titan KRIOS (2)||2011||80-300||FEI Falcon 4096x4096 (15 µm)||Single particle|
1 GIF = Gatan Imaging Filter
Tecnai F30 Helium (‘Polara’) microscope (left) as installed at the MPI of Biochemistry in Martinsried. This cryo-EM comprises a manual operated multispecimen stage (to load up to 6 samples) and it can be used either at liquid nitrogen or helium temperature. Titan KRIOS, a microscope in a box (middle, right image): the latest generation of computer controlled TEMs dedicated for cryo-EM, combining the latest technology in automation and robotics (especially for sample mounting; here up to 12 samples can be transferred at once in a robot called Autoloader).
The in-house developments include the design and manufacturing of hardware components and the design and implementation of suitable software routines to facilitate and further improve the applications in cryo-EM and especially cryo-ET. Hardware tools encompass the cryo-preparation/cryo-transfer/cryo-storage, dual-axis side entry cryo-holders and accessories for light/fluorescence microscopy at cryo-temperatures (see e.g. Correlative microscopy&FIB). Moreover we are actively involved in the exploration/testing and implementation of new approaches in electron microscopy, where we collaborate with the microscope and CCD camera suppliers. Software tools include the automation for the acquisition and analysis in cryo-EM and cryo-ET (see e.g. Software development).
Plitzko J.M.: Cellular cryo-electron tomography (CET)-Towards a voyage to the inner space of cells. In Single Cell Analysis. Edited by Anselmetti D: Wiley-VCH Verlag 39-68, 2009
Nickell S., Beck F., Scheres S.H.W., Korinek A., Förster F., Lasker K., Mihalache O., Sun N., Nagy I., Sali A., Plitzko J.M., Carazo J.M., Mann M. and Baumeister W: Insights into the molecular architecture of the 26S proteasome. Proceedings of the National Academy of Sciences of the United States of America 109:11943-11947, 2009
Ziegler A., Rockel B., Hegerl R., Freitag B., Lucken U., Plitzko J.M.: Aberration-corrected microscopy for structural biology applications. Journal of Microscopy-Oxford 233:170-177, 2009
Plitzko J.M. and Baumeister W.: Cryo-Electron Tomography (CET). In Science of Microscopy. Edited by Hawkes P, Spence J: Springer; 535-604. vol 1, 2006