Notes on Technic: Mahon's Myelin Stain for Celloidin-Embedded Nervous Tissue

Two methods commonly used to stain myelin sheaths are Kluver and Barrera's luxol fast blue (Kluver and Barrera 1953) and Weil's iron hematoxylin (Weil 1928). Both require differentiation of the stain; in addition, the Kluver-Barrera method specifies 16-24 hour staining. A third method for the selective staining of myelinated axons is that of Mahon (1938), which was introduced for use with paraffin-embedded autopsy tissue. The procedure possesses two distinct advantages since it requires: (1) no differentiation of the stain and (2) only 1 hour staining. Loyez's (1910) myelin stain for celloidin embedded tissue is similar to Mahon's but calls for long staining followed by differentiation. This report describes the application of Mahon's method to celloidin-embedded experimental tissue and emphasizes its utility for staining tissues to be used for reconstructing microelectrode penetrations (fig. 1) and for demonstrating the effect of experimental lesions (fig. 2).     

Thermoelectric Freezing for Attaching Nitrocellulose Blocks to the Microtome Stage

The routine production of large sections and of a few sections from a large number of blacks of tissue embedded in nitrocellulose often presents difficulties, large blocks often loosen if cemented to an intermediate carrier in the routine manner.     

Thermoelectric Freezing for Attaching Nitrocellulose Blocks to the Microtome Stage

The routine production of large sections and of a few sections from a large number of blacks of tissue embedded in nitrocellulose often presents difficulties, large blocks often loosen if cemented to an intermediate carrier in the routine manner.     

A Remodeled Tissue Flattener for Use with the International Microtome Cryostat

The antiroll plate is cut from a standard microscope slide, a 2 cm length, to give a 2 × 2.5 cm piece. This is fitted into inside grooves of a movable metal frame which is held by a hinge joint parallel to the back of the microtome knife. A stationary frame, which supports the hinged member, has spring clips welded to its sides for attachment to the knife. Clearance between the antiroll plate and knife is obtained by applying Scotch tape to the edge of the plate that is adjacent to the knife edge. The hinge permits the plate to be swung back and thus clear the knife surface.