Tomography

Electron tomography is an electron microscopy technique for obtaining 3D structural information. Images from EM sections (of various thickness) are collected at different tilt angles with electron microscope and this information is reassembled to yield 3D information. Reconstruction of this information is dependent on the use of Fourier-transformation algorithms and back projection. We employ two different methods for this purpose, TEM and STEM

Tomography through TEM employes sections from 100-250 nm and provides the best resolution with the limitation of fairly thin sections. 

Tomography through STEM employes sections of 250-1000 nm and thereby covers a larger volume than regular TEM tomography. The resolution in z-direction is slightly impaired, however still sufficient for most purposes. 

Both methods are done on our FEI TALOS 200 kV TEM can also be employed on serial sections to cover a larger volume. For reconstruction and modeling of the tomograms we combination eTOMO, IMOD and Amira.