Microtomes and microtome knives

Abstract

Microtome is a mechanical instrument used to cut biological specimens into very thin segments for microscopic examination. Biological specimens can be presented in many ways. But more often, these specimens are embedded in paraffin wax blocks and the commonest way of sectioning these specimens can be achieved by the microtome. The earliest form of the microtome enabled free hand sectioning of fresh or fixed material using a sharp razor. Modern microtomes are precision instruments designed to cut uniformly thin sections of a variety of materials for detailed microscopic examination. Central to the production of good sections is the microtome knife. Microtomy virtually begins and ends with a sharp, blemish-free cutting edge. The introduction of disposable blades has made easier the production of good quality, thin sections, but they are often unsatisfactory for sectioning harder tissues, especially bone. A sharp knife edge free from imperfections is essential for the production of good sections. Since many types of microtomes are commercially available in the market, choosing the right microtome is essential for producing the best result as required. A classification is proposed that unifies and organizes the various microtomes based on the mode of operation.