10. Aniline-oil, followed by xylol, blotting.
11. Xylol; balsam.
Celloidin is colorless, nuclei blue, tissue colorless, tubercle-bacilli red. Orange G may be used as a diffuse stain.
18. Lepra Bacillus. Gram-positive. Stain paraffin sections on warm carbol-fuchsin, as for the tubercle-bacillus. To differentiate from the tubercle-bacillus, stain 6-7 minutes in a dilute alcoholic solution of fuchsin, and decolorize in acid alcohol (nitric acid 1, alcohol 10). Lepra-bacilli stain; tubercle-bacilli do not.
c. Trichomycetes.
1. Actinomyces. Alcohol and formol fixation are best. Good preparations can be obtained with hæmatoxylin and eosin, Van Gieson’s or Weigert-Gram’s. The special staining methods advised give no better results than these simpler stains. Differential staining of clubs and mycelium may be obtained by Mallory’s method:—
1. Stain lightly in alum-cochineal. (Powdered cochineal 6 grms., ammonia alum 6 grms., water 100 cc. Boil half an hour, add water lost by evaporation, filter, add crystals of thymol.)
2. Saturated watery eosin 10 minutes.
3. Wash in water.
4. Stain in aniline gentian-violet 2-5 minutes.