Ultramicrotome Device and Ultramicrotomy

In the previous chapter, we covered the invention of microtome and its type and applications. As time advances, the microtome also modified and improved, thereby introducing an ultramicrotome where ultrathin (UT) sections are cut to study the ultrastructure of cellular organelles with its fine details in a transmission electron microscope (TEM) or scanning transmission electron microscope (STEM). UT sections are very thin slices of the specimen, sufficient to transmit the electron beam. Good quality UT sections (usually between 60- and 90-nm silver coloured) can provide a good image of the sample in TEM. It is imperative to cut UT sections of specimens to achieve images of the ultrastructure of biological samples or some specific material sample to conduct a TEM study. The method of cutting specimens into UT sections is called ultramicrotomy and is applied for biological sample preparation, both animal and plant tissue and some industrial materials such as polymers, membranes, plastic, and soft metals, etc., used for visualising and analysing the internal fine structure of samples/specimens at nanometre scale resolution, that can be studied and documented at different magnifications in a TEM or STEM. Ultramicrotomy procedure lies in a very crucial but essential position for TEM or STEM study. Only a perfect section can produce a perfect micrograph of a specimen in TEM or STEM, and a perfect block can reach a perfect section if all the parameters/steps of ultramicrotomy procedures are performed flawlessly, which are relatively critical and tedious.