A High Speed Microtome for the Electron Microscope

Two forms of a high speed type of microtome are described which are able to cut cross sections to the thinness required for electron microscopic study (0.1 to 0.8 micron, depending on the material). Techniques of microtome operation are suggested together with a few methods of sample preparation and subsequent section treatment, namely, collecting, selecting, and mounting. Embedding materials which sublime readily are described; these have been used successfully with this high speed microtome to support many types of materials. These volatile embedding materials have the advantage that they eliminate the difficulties that on some occasions arise with the use of solvents in the process of solvent extraction of embedding materials, such as Carbowax and paraffin, from the sections. A number of photographs are shown of the high speed microtome as well as electron micrographs of a few sections produced by the instrument. These pictures of rubber, rayon, Lucite, block Nylon, and animal tissue indicate some of the fields of application of the microtome and demonstrate the effectiveness of the necessary auxiliary techniques for it, particularly sample hardening and embedding, and section collecting and mounting.