Plastic Embedding of thick Celloidin Sections of nerve Tissue

A method is described for mounting Golgi-impregnated and Weigert-stained thick celloidin sections of brain and spinal cord in transparent plastic. Finished mounts have good optical properties and are suitable for macroscopic and microscopic observation. The durability of such preparations makes them superior to similar material prepared by the more conventional methods. Holes of suitable size were cut in matrices of 2.5 × 5 × 3/16 inches Plexiglas. Ward's Bio-plastic was used to form a base for the holes and also as the embedding medium for the sections. Plate glass formed a working substrate and gave a polished surface to the plastic base and later to the top of the preparation. For Golgi material (200μ) the celloidin was removed by dioxane. A dioxane-plastic bath preceded plastic embedding. For Weigert material (30-40μ) celloidin was not removed due to fragility of sections. Prior to plastic embedding, they were subjected first to benzol and then to a benzol-plastic bath.