STAINING SOLUTIONS 139 



U una's polychrome Hue. 



Unna's polychrome blue solution (Griibler), - - 100 c.c. 



Carbolic acid crystals, - 1 gram. 



90 per cent, alcohol, - - 10 c.c. 



Distilled water, - - Q.S. to 100 c.c. 



Dissolve the carbolic acid in the alcohol, add sufficient water to make up to 

 80 c.c. and then add the polychrome blue. 



(ii) Aniline solutions. 



These solutions keep badly and should be freshly prepared every time they 

 are wanted. They have no advantage over carbolic solutions and are gradu- 

 ally dropping out of use. 



In preparing them, the following solution must first be made up : 



Aniline oil water. 



Aniline oil, - 5 c.c. 



Distilled water, - - 100 



Mix the oil and water in a yellow glass bottle, shake vigorously and leave 

 them in contact. Just before use filter the solution through a previously 

 moistened filter paper. See that no fine droplets of oil pass through the filter 

 as this would spoil the results of the staining ; should this accident occur, 

 filter the solution again. 



Ehrlich's aniline-violet. 



Filter into a porcelain dish about 10 c.c. of aniline oil water. To the 

 filtrate add a few drops of a filtered alcoholic solution of gentian-violet until 

 an iridescent pellicle appears. Use the solution at once. It should be freshly 

 prepared every day. 



Aniline-fuchsin, aniline-crystal-violet and aniline-methylene-blue are all 

 prepared in the same way. 



(iii) Alkaline solutions. 



These solutions have been extensively used in Germany. - Almost the only 

 alkaline solution now used however is Lceffler's alkaline methylene blue. 

 Sorrel's blue (vide Hcematozoa) is an alkaline dye. [Borax blue also is not 

 infrequently used for staining some of the hsematozoa (q.v.).] 



Loeffler's alkaline methylene blue. 



Alcoholic solution of methylene blue, - 30 c.c. 



1 in 10,000 aqueous solution of caustic potash, - - 100 



Mix in a bottle and filter before use. This solution is rapidly decomposed by 

 the caustic potash combining with the C0 2 of the atmosphere. 



Kuhne's alkaline blue. 



Alcoholic solution of methylene blue, - 30 c.c. 



1 per cent, aqueous solution of ammonium carbonate, - 100 ,, 



Mix and filter before use. This solution keeps better than Lceffler's. 



(iv) Perchloride solutions. 



Nastikow's violet. 



1 in 2000 aqueous solution of perchloride of mercury, - 10 c.c. 



Alcohol solution of gentian-violet, - 1 



Mix and filter. This stain does not keep well. 



