Conclusion
Although STEM is mainly used in materials sciences, there are many
applications in biology that would benefit from STEM imaging. However,
until now very few groups have explored the potential of STEM imaging.
The aim of this review was to describe the STEM methods used in
parasitology and other fields. We have demonstrated using several
examples that STEM and cryo-STEM are superior to TEM and cryo-TEM under
specific conditions. STEM methods perform remarkably well with thick
samples. Since parasites are thick samples, STEM imaging can be
particularly beneficial. Cryo-STET in particular, is a perfect fit for
the study of micrometre thick samples as they can simply be deposited or
grown directly on electron microscopy grids, which makes sample
preparation protocol easier and faster to execute.
Another important detail of STEM imaging is its relative low cost
compared to the acquisition of a TEM-related equipment (direct electron
detector, energy filter). Electron microscopes used in biology are more
and more often equipped with STEM detectors. Because STEM is now being
used for more than a decade, there are many tools available, from data
collection to image analysis. The transition from room temperature to
cryo-conditions will be motivated by the possibility to i) recover
native structural information and ii) perform CLEM experiments. These
events are a huge benefit for the scientists who would like to ride on
the STEM wave and want to join cutting-edge technologies.