A microtome is used to cut thin slices of material for microscopic examination. Different designs and cutting components are used depending on the material and microscope. Histology is the study of biological sections. Microtomes can use metal, glass, diamond or laser blades. Handheld microtomes are available for less rigorous applications.
A microtome is a device used to cut extremely thin slices of material into specimens called sections. Typically, this is done when preparing objects for microscopic examination. Microtomes are available in a number of designs using different cutting components. This is to adapt to the physical properties of the material to be prepared and the type of microscope to be employed. The microscopic study of biological sections is called histology.
In a slide microtome, the material to be sectioned is held in a sliding shuttle that moves across the surface of a blade. To prepare the material for slicing, an infusion of paraffin wax or an epoxy cures the sample into a solid. The sample is then inserted into the microtome shuttle. Different blade designs are used, depending on the consistency of the sample and the required section thickness. The blades can be metal, glass or diamond.
The cutting blade, or knife, in a rotating microtome is also in a fixed position relative to the specimen. The rotational motion of a flywheel is translated into the horizontal motion of a sample across the knife. Typically, lowering the sample into position is done manually using a control wheel. This feature has been automated in recent rotary designs, allowing for more precise sectioning.
A rotary microtome model is usually employed when cryogenic conditions are required. Sectioning takes place in a liquid nitrogen chamber, allowing the sample to be hardened to a glass-like state. The rotary design is also used in ultramicrotome sampling where extremely thin sections are required. Very tight manufacturing tolerances are required to ensure the accuracy needed to prepare sections for electron microscopy. Cutting blades are usually made with gem-quality diamonds.
Unlike mechanical micritomes, which make physical contact with the sample, laser microtomes do not require sample preparation. The cutting device is a pulsed infrared laser. This allows for very precise sampling control and is equally applicable to soft tissue and hard materials such as bone. Eliminating physical contact with the sample material eliminates much of the possibility of contamination.
For less rigorous applications, the student or hobbyist could use a handheld microtome. These devices allow tissue sections to be taken for slide preparation, albeit with much less precision than laboratory instruments. The sample material is held firmly by the device and advanced into the cutting position in precise increments. The section is then taken manually with a razor.
Protect your devices with Threat Protection by NordVPN
