A New Method of Sectioning Synthetic Fibers with the Ultra-Microtome for Examination with the Electron Microscope

Abstract

A method has been devised in which a piece of rayon or nylon yarn, consisting of 10 or 20 single filaments, is prepared for sectioning with the high-speed ultra-microtome † in such a way that the boundaries of individual filaments can be identified when viewed in the electron micro scope. The yarn is mounted in a special holder in which the filaments are spread out radially. They are then coated with a thin film of evaporated gold in the vacuum unit. These filaments are allowed to fall parallel to each other again. They are embedded in a very thin layer of low- melting-point paraffin and sectioned with the ultra-microtome. The thin film of gold enables one to determine whether the area being studied is near the surface of the filament.