Materials Problems and Approaches for TEM and TEM/STEM Analyses - Sample Preparation Topic for Transmission Electron Microscopy - page 67

(b)
Electron Beam
Thickness:
50 nm-70 nm
Ultramicrotomic Slice Viewed in its Volume
View of the Same Slice on the Microscope Screen
Fig. 4.6 ( a ) TEM bright-field image of a thin section of retrovirus particles on a cell. ( b )Diagram
of the projection of the section on the image observation plane ( A. Rivoire, EZUS CT μ université
Cl. Bernard - Lyonl - Villeurbanne )
makes it impossible to determine whether they are on the same level as the cell or
on a different plane through the thickness of the sample.
The recognition of structures (called ultrastructure by biologists) helps to deduce
their biological functions (Figs. 4.7, 4.8) . The approach to the phenomena of syn-
theses or degradation of cellular components will use observations combined with
preliminary labeling techniques. Investigations of structural defects and/or con-
taminants can reveal pathology. The sample preparation technique is of utmost
importance with regard to the type of observation, which is usually reduced to
bright-field imaging mode.
Fig. 4.7 TEM image of a
thin section of a renal
glomerulus, an organ
structure with its different
types of cells ( J. Boumendil
CMEABG, Université Claude
Bernard-Lyon 1
Villeurbanne )
Statistical analysis of the shape, size, and distribution of a component is some-
times correlated with the morphological analysis. The investigation of serial sections
is indispensable to understanding the cell or tissue. With the help of specialized
software, their study can produce a 3D reconstruction.