100 A MANUAL OF BACTERIOLOGY 



solution of gentian violet, 1 part ; 5 per cent, aqueous solution of 

 carbolic acid, 10 parts). 



For anilin gentian violet two stock solutions may be employed, 

 and these seem to keep indefinitely, viz. : 



No. 1 

 Gentian violet ...... 2 grm. 



Anilin ........ 9 c.c. 



Alcohol (95 per cent.) ..... 33 c.c. 



No. 2 

 Gentian violet ...... 2 grm. 



Distilled water 100 c.c. 



For use, mix 1 c.c. of No. 1 with 9 c.c. of No. 2, and filter ; this 

 mixture will keep for about a fortnight. 



(4) Carbol-fuchsin (Ziehl-Neelsen solution) : 



Fuchsin ....... 1 part 



Absolute alcohol . . . . . . 10 parts 



Five per cent, aqueous solution of carbolic acid . 100 parts 



The fuchsin is dissolved in the absolute alcohol and then mixed 

 with the carbolic acid solution. It must always be filtered before 

 use. 



An intense staining solution. For films it is best diluted with 

 five to ten parts of water ; stain for two to five minutes. 



(5) Carbol-thionine blue (Nicolle) : 



Saturated solution of thionine blue in alcohol 



(90 per cent.) 10 c.c. 



One per cent, aqueous solution of carbolic acid . 100 c.c. 



Sections can be stained in from a few minutes to half an hour. 

 This solution may be used for a modified Gram's method (see 

 p. 106). Can be substituted for methylene blue for all purposes, 

 and is more permanent than the latter. 



(6) Eosin (alcohol-soluble and water-soluble) : 



A somewhat diffuse stain. Is used for counter-staining the 

 tissues in Gram's method, and for staining red blood-corpuscles 

 and acidophile granules in leucocytes. 



A | to 1 per cent, aqueous or alcoholic solution may be used, 

 and the staining should not, as a rule, be prolonged for more than 

 about half a minute. 



