Rapid Single-Solution Polychrome Staining of Semithin Epoxy Sections using Polyethylene Glycol 200 (PEG 200) as a Stain Solvent

Abstract

Rapid, onestep polychromatic staining of 0.75-1.5 μm epoxy sections of glutaraldehyde-osmium fixed tissues can be obtained with mixtures of basic fucbsin and toluidme blue O in alkaline polyethylene glycol ZOO (PEG ZOO). Sections are attached to slides by heating at 100 C for 45 seconds and stained at that temperature for 2-3 minutes with a solution consisting of PEG 200 (50 ml), 0.2 N KOH (0.75 ml), basic fuchsin (1.7 gm), and toluidine blue O (0.3 gm). Red-blue balance and selective staining of different structures can be controlled by varying the amount of toluidine blue added. After rinsing with 10% acetone and rapid drying, sections are covered with immersion oil or mounting medium and a cover-slip. Total time from cutting of a section to finished preparation is less than 6 minutes. This staining solution is stable, does not produce precipitates on the sections, and does not wrinkle or lift the sections from the slides.