Related Experiment Video
Updated: Aug 16, 2026

Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography
Published on: March 12, 2017
The top-bottom effect of a tilted thick specimen and its influence on electron tomography
Chao Yang1, Hai-Bo Zhang, Jing-Jing Li
1Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
Abstract:
We present the top-bottom effect (TBE) of a 5 microm thick amorphous specimen in a 3 MV ultrahigh voltage electron microscope (ultra-HVEM) and its influence on the quality of electron tomography (ET). The 40-nm gold particles on the top surface of the specimen tilted at different angles have been observed to be of poorer image quality than those on the symmetrical bottom surface obtained by tilting and turning over the specimen. The point spread function of the gold-particle images was calculated using the increment Wiener filter and the image-quality variation was then evaluated. The TBE is shown to become more remarkable with the increase of the effective thickness of the tilted specimen or the decrease of the magnification of the ultra-HVEM. The ET simulation indicates that the TBE may generate approximately 4% distortion in the radial direction of a reconstructed sphere model.
More Related Videos
Related Concept Videos
Electron Microscope Tomography and Single-particle Reconstruction
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Transmission Electron Microscopy
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Scanning Electron Microscopy
Fundamental Principles
Accelerated...

