The RTG welcomes Dr. Sharon Wolf from the Weizmann Institute of Science as a Guest speaker on Tuesday, 26th of September 2017.
Titel: “Cryo-scanning Transmission Electron Tomography – a 3D view into cell architecture and chemical composition“
We have recently been developing CryoSTEM tomography (CSTET), a novel combination of two well-established techniques: cryo-electron tomography (CET) and scanning transmission electron microscopy (STEM). Cryogenic fixation allows for the most faithful preservation of biological macromolecules, tissues and cells. By preserving the cryogenic temperature and maintaining a contamination-free environment inside the electron microscope, CET from thin (~300 nm) cryo-preserved specimens have resulted in major advances in their characterization. However, limitations on sample thickness are severe, due to the dependence on phase contrast for interpretable signal. STEM provides an interesting alternative because signal is provided incoherently, with contrast provided by variations in mass thickness and atomic number, and the limit for sample thickness is extended three-fold. While the bright-field STEM data provides excellent morphological information, the simultaneously collected dark field signal provides information on chemical content, due to its sensitivity to atomic number. In addition, EDX and EELS analysis can provide on-the-spot chemical characterization.
We have used CSTET to characterize calcium phosphate deposits in the mitochondria of a variety of human cell types. We found such deposits to be ubiquitous in normally growing cells. Results and interpretations of such studies will be discussed.
Official Announcement: RTG1962_Wolf
Venue: Department Biology, Building B1, Floor 00, Seminar Room Cell Biology (00.581), Staudtstraße 5, 91058 Erlangen.
Time: 5.00 p.m. (s.t.) –> Drinks will be served, starting at 4.30 p.m.