Microtomes And Microtome Knives ' A Review And Proposed Classification

ABSTRACT

Microtome is a mechanical instrument used to cutbiological specimens into very thin segments formicroscopic examination. Biological specimens can bepresented in many ways. But more often, thesespecimens are embedded in paraffin wax blocks andthe commonest way of sectioning these specimens canbe achieved by the microtome. The earliest form of themicrotome enabled free hand sectioning of fresh orfixed material using a sharp razor. Modern microtomesare precision instruments designed to cut uniformlythin sections of a variety of materials for detailedmicroscopic examination. Central to the production ofgood sections is the microtome knife. Microtomyvirtually begins and ends with a sharp, blemish-freecutting edge. The introduction of disposable blades hasmade easier the production of good quality, thinsections, but they are often unsatisfactory forsectioning harder tissues, especially bone. A sharp knifeedge free from imperfections is essential for theproduction of good sections. Since many types ofmicrotomes are commercially available in the market,choosing the right microtome is essential forproducing the best result as required. A classificationis proposed that unifies and organizes the variousmicrotomes based on the mode of operation.