Scanning transmission ion micro-tomography (STIM-T) of biological specimens.
Computed tomography (CT) was applied to sets of Scanning Transmission Ion Microscopy (STIM) projections recorded at the LIPSION ion beam laboratory (Leipzig) in order to visualize the 3D-mass distribution in several specimens. Examples for a test structure (copper grid) and for biological specimens (cartilage cells, cygospore) are shown. Scanning Transmission Micro-Tomography (STIM-T) at a resolution of 260 nm was demonstrated for the first time. Sub-micron features of the Cu-grid specimen were verified by scanning electron microscopy. The ion energy loss measured during a STIM-T experiment is related to the mass density of the specimen. Typically, biological specimens can be analysed without staining. Only shock freezing and freeze-drying is required to preserve the ultra-structure of the specimen. The radiation damage to the specimen during the experiment can be neglected. This is an advantage compared to other techniques like X-ray micro-tomography. At present, the spatial resolution is limited by beam position fluctuations and specimen vibrations.
Schwertner
Micheal
M
Fakulät für Physik und Geowissenschaften, Nukleare Festkörperphysik, Universität Leipzig, Linnéstrasse 5, D-04103, Leipzig, Germany. micheal.schwertner@eng.ox.ac.uk
Sakellariou
Arthur
A
Reinert
Tilo
T
Butz
Tilman
T
D002356:Cartilage / Q000648:ultrastructure; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008853:Microscopy / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D011522:Protons; D013170:Spores / Q000648:ultrastructure; D014056:Tomography, X-Ray / Q000379:methods*
D011522:Protons