Friedlaender’s Staining Methods.—Cover-glass preparations are treated for 3 minutes with a 1 per cent. solution of acetic acid, and allowed to dry after removal of excess of liquid by filter paper. Next place them in gentian violet aniline water (aniline water, 100 C.c., concentrated alcoholic solution of gentian violet, 11 C.c.; absolute alcohol, 10 C.c.) for half a minute, wash in water, mount and dry in balsam. Sections are kept for 24 hours in a warm place, in the following solution:—Concentrated alcoholic solution of gentian violet, 50 C.c.; distilled water, 100 C.c.; glacial acetic acid, 10 C.c. Then treat for 1 or 2 minutes with 0·1 per cent. acetic acid, dehydrate, clear, and mount in balsam.
Gaffky’s Staining Methods.—Sections of material hardened in alcohol are left for 20 to 24 hours in a deep blue opaque solution, freshly made by adding saturated alcoholic solution of methylene blue to distilled water. Then wash in distilled water, dehydrate in absolute alcohol, clear in turpentine oil, and mount in balsam.
Giacomi’s Staining Method.—Stain cover-glass preparations for a few minutes in a hot solution of fuchsine, then place in water containing a few drops of ferric chloride solution, and afterwards decolourise in strong ferric chloride solution. If any precipitate be formed with the iron solution, complete the decolourisation in alcohol. Counterstain with vesuvine.
Gibbes’ Double Staining Method.—Well mix magenta, 2 Gm., and methylene blue, 1 Gm., then add slowly aniline oil, 3 C.c., dissolve in rectified spirit, 15 C.c. Subsequently add 15 C.c. of distilled water and keep the stain in a stoppered bottle. Cover-glass preparations are placed for 4 minutes in the slightly heated stain and sections left for some hours in the stain at the ordinary temperature. Afterwards, wash in methylated spirit until no more colour comes away, then dehydrate, clear in cedar oil, and mount in balsam.
Gibbes’ Magenta Stain.—Mix magenta, 2 Gm.; aniline oil, 3 Gm.; rectified spirit, 20 C.c.; and distilled water, 20 C.c.
Golgi’s Sublimated Method.—Small cubes of tissue are hardened for 15 to 30 days in Müller’s fluid, which should be frequently changed. Then transfer for 8 to 10 days to 0·25 to 1 per cent. aqueous mercuric chloride solution, which must be changed, as it becomes coloured. If desired, treat subsequently with weak sodium sulphide solution to darken the stain and make it sharper. After cutting sections from material thus prepared they must be well washed with water.
Gram’s Stain for Bacteria.—This is prepared by shaking 15 drops of aniline oil with 15 Gm. of water, filtering the solution and adding to the filtrate 4 to 5 drops of saturated alcoholic solution of gentian violet. Or shake 3·3 C.c. of aniline with 100 C.c. of distilled water and, after filtering, add 11 C.c. of concentrated alcoholic solution of gentian violet and 10 C.c. of absolute alcohol. After preparations have been stained for 1 to 3 minutes in one of the above they are quickly rinsed in absolute alcohol and then placed in Gram’s solution of iodine in potassium iodine (iodine, 1 Gm.; potassium iodine, 2 Gm.; water, 300 C.c.), until they have acquired a brown colour. This takes about 1 to 3 minutes, and they are next washed in 90 per cent. alcohol until they become pale yellow, then dehydrated, cleared, and mounted in balsam. Counterstain with eosine or vesuvine if desired.
Gram’s Solution.—Iodine, 1 Gm.; potassium iodine, 2 Gm.; distilled water, 300 Gm.
Grenacher’s Alum Carmine.—Dissolve 5 Gm. of ammonium alum in 100 C.c. of distilled water, add 1 Gm. of carmine, and boil for 20 minutes, filter when cool, and add distilled water to make up to 100 C.c.
Grenacher’s Alcoholic Borax Carmine.—Dissolve 4 Gm. of borax in 100 C.c. of distilled water, then add 3 Gm. of carmine, and heat gently. Finally, add 100 C.c. of 70 per cent. alcohol, filter the solution, if necessary, before use. Pieces of tissues are stained in this for 1 to 3 days, and then transferred to 70 per cent. alcohol, containing 0·5 to 1 per cent. of hydrochloric acid.