138 STAINED PREPARATIONS 



The above proportions give a saturated solution and there should be an 

 excess of the dye at the bottom of the bottle. 



These solutions are very little used : they do not keep well and should 

 be prepared as required. They stain slowly but sharply. 



Aqueous solutions of quinoline blue, vesuvin, methyl-green and neutral- 

 red are used for staining living organisms. 



B. Staining solutions containing a mordant. 



(i) Carbolic acid solutions. 

 These are more used than any other stains and retain their properties 



for a very long time. . , 7 , , , . , . 



Liehl s carooi-juchsin. 



Basic fuchsin, 1 gram. 



Carbolic acid crystals, - 5 grams. 



Absolute alcohol, - 10 c.c. 



Distilled water, - - 100 



Rub up the fuchsin and alcohol in a glass mortar, add the carbolic acid and 

 mix ; add two-thirds of the water little by little, stirring all the time ; pour 

 the mixture into a bottle then rinse out the mortar with the remainder of 

 the water and add it to the mixture in the bottle. Leave for 24 hours before 

 filtering into a clean ground-glass stoppered bottle. 

 A diluted solution prepared as follows is often used : 



MJ X Dilute carbol-fuchsin. 



Ziehl's carbol-fuchsin, - 1 c.c. 



Distilled water, - 3 to 10 c.c. 



Mix and filter just before use. 



Carbol-gentian- violet (Nicolle) . 



Gentian-violet. - 1 gram. 



Carbolic acid crystals, - 2 grams. 



Absolute alcohol, - - 10 c.c. 



Distilled water, - - 100 



Prepare as in the case of carbol-fuchsin. Use as such. This solution is 

 chiefly used for Gram's stain. 



Carbol-crystal-violet ( Roux) . 



Substitute crystal-violet for gentian-violet and prepare in the same way 

 as the preceding solution. 



Crystal-violet has the advantage over gentian-violet of being a well-defined 

 crystalline compound. Gentian-violet is an amorphous product which varies in 

 composition. Crystal- violet however is not so powerful a dye as gentian- violet. 



Carbol-thionin (Nicolle). 



Thionin, 0'5 to 1 gram 



Carbolic acid crystals, - 1 gram 



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



Distilled water, - - 100 



Prepare in the same way as carbol-fuchsin. This stain is recommended for 

 sections and films ; it stains rather more slowly but gives better results than 

 crystal-violet and gentian-violet and does not overstain. 



Carbol-methylene-blue (Kuhne). 



Methylene blue, 

 Carbolic acid crystals, 

 Absolute alcohol, - 

 Distilled water, 



Prepare in the same way as the foregoing solutions. 



1*5 to 2 grams. 

 2 grams. 

 10 c.c. 



100 , 



