Rotary Microtomes

How to Use Rotary Microtome

rotary microtomes — Mon, 14 May 2007 03:39:14 +0000

A rotary microtome is primarily used for cutting sections of frozen tissue as well as pastes, powders and some food substances. This microtome is contained in a refrigerated chamber, at a temperature of which can be maintained at a preset level by cryostat. Since it is difficult to cut very thin sections from soft embedding compounds, the hardness of the embedding compound also matters because it reflects the thickness at which sections can be cut. Animal and human tissues are too soft when fresh to be cut thinly. Some form of pre-treatment is required to harden the tissue to facilitate cutting thin sections. Freezing or embedding tissues in a medium which offers support for cutting. To firm tissues enough for sectioning, they are frozen in a cryomatrix eg. OCT Compound. It operates at temperatures of –40-0ºC and is able to cut sections 0.5-300 μm in thickness. A full rotary microtome action is robust enough to cut even very hard specimens such as decalcified bone. (more…)

History of Rotary Microtome

rotary microtomes — Mon, 14 May 2007 03:38:42 +0000

In early the 20th century, the rocking microtome, comprising three moving parts, is extremely reliable. It was designed only for cutting paraffin sections the tissue moves through an arc as it advances towards the knife which is held rigid causing the sections to be cut in a curved plane. Although rocking microtome has been re-appearing in portable cryostats, disadvantages like limitation in size of a specimen to be cut, lightness of its frame and its tendency to move during cutting process pave the way for more precise rotary microtome to replaced it. (more…)

An Introduction to Rotary Microtome

rotary microtomes — Mon, 14 May 2007 03:38:00 +0000

The freehand sectioning of fresh or fixed material using a sharp razor was the earliest form of microtomy. Today, microtome are instruments designed to accurately cut equally thin sections of various materials even those tiny one’s only visible using microscopes. For light microscope, where magnifications can reach up to 1,800x, the thickness of a section can vary between 1 and 10 microns (thin sections). While for electron microscope, where magnifications of several hundred thousands are possible, the thickness of a section is usually of the order of 10 nanometres (ultra-thin sections). Microtomes are made up of three main parts. The base as the main body; the knife and knife holder that perform the slicing and lastly, the material or tissue holder, in order to keep the specimen in place while cutting. Microtomy styles vary depending on the functions and usage required. Amongst it is the Rotary Microtome. (more…)