Some Synthetic Resins IN Combined Fixing, Staining and Mounting Media

Abstract

Many of the recently devised plasticizers and resins can be utilized to advantage in cytological technics. Some of them have solubilities which enable us to incorporate them in such fixing and staining solutions as aceto-carmine and propiorric-carmine. They are non-volatile, do not alter the fixation images of the fluids with which they are mixed, and serve as mounting media as the volatile components evaporate. Thus it is possible to make a permanent slide in a single operation. These newer compounds are better adapted for this technic than are the natural balsams which have been used previously, as their greater tolerance for water provides a much greater margin of safety. Procedures are described for the utilization of (1) Rezyl 7020, a water-soluble resin (now, unfortunately, not available), which dries to form a water insoluble film, (2) Amberol 750 and (3) Bakelite BR-7160, two alcohol soluble resins, more miscible in solutions containing water than are the natural balsams. Formaldehyde can be included in the aceto-carmine and propionic-carmine fluids with the result that more nuclear detail is preserved. Lacto-gelatin has some valuable properties as a mounting medium and can be used when the specimen is stained with orcein. Carmine, which gives a permanent stain in Rezyl 7020, Amberol 750 and Bakelite BR-7160 fades in lacto-gelatin.