Kühne’s Aniline Oil Solutions.—Rub up as much methylene blue, methyl green, or safranine as will go upon the point of a knife, with 10 C.c. of aniline, and allow to settle.
Kühne’s Carbolic Fuchsine or Black Brown.—Dissolve 1 Gm. of fuchsine or black brown in 10 C.c. of absolute alcohol, and add 100 C.c. of a 5 per cent. aqueous solution of carbolic acid.
Kühne’s Modification of Gram’s Method.—Stain nuclei with carmine, then treat sections for 5 minutes in methyl violet solution, diluted one-sixth with a 1 per cent. aqueous solution of ammonium carbonate, or in a solution of Victoria blue, 0·25 Gm., in rectified spirit, 20 C.c., and distilled water, 80 C.c. Next rinse thoroughly in water and transfer to Grain’s solution for 2 to 3 minutes; again rinse in water and extract excess of stain with solution of yellow fluorescine, 1 Gm., in absolute alcohol, 50 C.c. Finally, pass through pure alcohol, aniline, terebene, and xylol, and mount in balsam.
Löffler’s Solution.—Concentrated alcoholic solution of methylene blue, 30 C.c.; solution of (caustic potash) potassium hydrate (1:10,000), 100 C.c. Mix and filter shortly before use. Sections are stained for a few minutes (tubercle sections for some hours), and excess of stain can be removed by immersion for a few seconds in 0·5 per cent. acetic acid. Dehydrate in absolute alcohol, clear in cedar oil, and mount in balsam. Löffler found that most bacteria stained better in this solution than in the weaker solutions used by Koch for turbercle bacillus.
Lavdowsky’s Bilberry Juice Stain.—Well wash the fresh berries of Vaccinium myrtillus, then express the juice and mix with twice its bulk of distilled water, mixed with a little 90 per cent. alcohol. Heat for a short time and filter whilst warm. Dilute the stain with 2 or 3 volumes of distilled water before use.
Lee’s Formaldehyde Solutions.—(1) Mix 1 part of 40 per cent. formaldehyde solution with two parts of 1 per cent. chromic acid solution, and add 4 per cent. of acetic acid. (2) Mix 1 part of 40 per cent. formaldehyde solution with 4 parts of 1 per cent. platinic chloride solution, and add 2 per cent. of acetic acid.
Lee’s Osmic Acid and Pyrogallol Stain.—Fix the tissues in Hermann’s mixture or Flemming’s mixture for half an hour, then place in a weak solution of pyrogallol, which may be prepared with alcohol in some cases. Safranine may be used as a second stain.
Martinotti’s Picro-nigrosine Stain.—Pathological objects are stained for 2 or 3 hours or days, in a saturated solution of nigrosine in saturated alcoholic picric acid solution. Then wash out in a mixture of 1 part of formic acid with 2 parts of alcohol until the grey matter appears clearly differentiated from the white to the naked eye.
Mayer’s Aluminium Chloride Carmine.—Dissolve 1 Gm. of carminic acid and 3 Gm. of aluminium chloride in 200 C.c. of water.
Mayer’s Berlin Blue Injection.—Add a solution of 10 C.c. of tincture of ferric chloride in 500 C.c. of water, to a solution of 20 Gm. of potassium ferrocyanide in 500 C.c. of water, allow to stand for 12 hours, decant, wash the deposit for 1 or 2 days with distilled water until the washings come through dark blue, then dissolve the blue in about a litre of water.