A Microtome refers to a precision instrument used to slice precision slices from a block of tissues accurately. There are different types of microtomes used to slice paraffin and plastic embedded tissues. There are also special microtomes used to section frozen tissues. But what all microtomes have in common is that a sharp blade and the tissue block are held in a fixed position to each other to produce very thin slices of the tissue.
How does a microtome work?
For one to study or analyze specimens at the microscopic level, the specific tissue being examined must be cut using a microtome to produce very thin slices. A precision microtome is especially beneficial because it can make slices of desired or uniform thickness for microscopy. Unlike freehand slices, tissue slices cut with a microtome are free from damage as the instrument is highly precise and accurate. The cut tissue is then floated over a water bath to prevent wrinkling and distortion of the tissue, and the scientist picks it up on a slide. The slide can be charged or uncharged based on the kind of tissue being cut and its staining rules. The use of a cool drying technique boosts the morphology of obtained tissue sections.
The main applications of microtomes
Routine histological technique
During the study of histology, scientists harden tissues by replacing water with alcohol. After the tissue hardens, a microtome is used to cut and create slices of different thicknesses. Sliding and rotary microtomes are commonly used. Although they have varying working mechanisms, they both produce uniform slices with high precision.
Crysectioning is commonly used to create frozen slices for microscopic analysis. Unlike histology, scientists first freeze water-rich tissues in the cryostat before slicing them. The microtome is usually located within the cryostat. Cryosectioning is a very beneficial technique when the tissue needs to be analyzed in the shortest time possible. Unlike other techniques, cryosectioning makes it possible to study the cells and other specimens’ components in their native state.
Botanical microtechnique refers to the study of plant specimens under microscopy in botanical histology. Therefore, a microtome can produce these sections of the tissue to be analyzed or studied under the microscope. Unlike animal specimens that may be softer, plant specimens are hard, which needs microtome knives. These are specifically useful in slicing harder and rigid materials, including plants and bones. However, plant specimen sections tend to be thicker than animal specimen slices.
Tissue processing is a very crucial step that comes before tissue sectioning. It involves removing water from the tissues to replace it with a solidifying medium. Most tissues are usually very soft, which presents a challenge when trying to cut them to obtain thin, precise sections from microscopy. That is why it is necessary to harden them to make it easier to slice them. A microtome helps cut very thin and exact slices for study under the microscope after the tissue processing.
Microscopy is a very integral part of biological studies especially analyzing cell structures. The sectioning process, an essential part of sample preparation, is easy thanks to high precision microtomes.