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English

Latest developments in Cryo EM
Marc Storms (FEI Company)

日時

April 19, 2012 (Thu), 13:00-15:00

場所

3F Seminar room, Nanobiology Building

演者

Marc Storms (FEI Company)

演題

Latest developments in Cryo EM

要旨

Fundamental research within the scope of cell biology and structural biology is increasingly focusing on unraveling interactive biological and biochemical processes and pathways at the macromolecular level. For this, high resolution transmission electron microscopy (TEM) is indispensable. Of paramount importance is the three-dimensional visualization of macromolecular structures and molecular machines in their native hydrated state. Recent developments in computer hardware (GPU processing) enable processing of enormous Single Particle datasets, previously only in reach for labs with access to big (costly) CPU computer clusters. With ever improving resolution needs, and the desire to solve asymmetric structures as well as multi-conformational states of macromolecules, the Structural Biology field demands ever increasing datasets - of course preferably taken in as little time and with as little training as possible, without compromising on data quality. To satisfy this need, FEI developed an intuitive Single Particle acquisition package (EPU) enabling automated data collection on Tecnai and Titan microscopes. In combination with the latest FEI instrument for Structural Biology (Titan Krios), the EPU package facilitates multiday automated high-throughput experiments. Single Particle data collection is greatly simplified and the time needed to spend at the instrument is significantly reduced. Single Particle Analysis (SPA) and Tomography provide complementary information: SPA can deliver high resolution images of a molecular complex, but it is taken out of its biological context. Cryo Electron Tomography (CET) can obtain information on the position of a complex, but the resolution of individual particles is limited. Template matching is a technique that has been explored for some time now as a tool to bridge the gap between the two regimes. FEI has developed a software package, ARGOS (Automated Recognition of Geometries, Objects and Segmentations), that can do a full 6D template search on a (dedicated) single desktop PC with the speed of a medium sized cluster. The quality of cryo-images is largely hampered by the electron dose the sample can withstand. Therefore the sensitivity of the detector is crucial. In order to improve this sensitivity FEI has developed the fully embedded Falcon, a direct electron detector with a three times better DQE than current high sensitive CCD cameras. The next generation Falcon (upgradable) will even further improve the DQE by almost a factor of two. In this presentation we will discuss the latest software developments on automated Single Particle acquisition (EPU) and Template Matching (ARGOS), as well as the latest hardware developments on the Falcon detector.

世話人

Keiichi Namba
Tel: 06-6879-4625
E-mail: keiichi[at]fbs.osaka-u.ac.jp