For staining flagella of bacteria use actively motile organisms 20 to 24 hours old, allow to diffuse in sterile water 20 to 30 minutes, transfer droplets of the suspension to clean slides and let evaporate without spreading. Then treat 2 to 4 minutes with the following mordant: tannic acid 10 or 20%, 50 cc.; ferric chloride 5%, 10 to 15 cc.; carbol fuchsin (Ziehl-Nielson), 5 cc.; hydrogen peroxide 3%, 6 to 8 cc. Wash and stain 2 to 3 minutes with a mixture of basic fuchsin, saturated alcoholic, 10 cc.; anilin oil (1 part) and 95% alcohol (3 parts) mixed, 5 cc.; distilled water, 30 cc.; acetic acid, 4%, 1 cc. Wash thoroly with water.
