STAINING SOLUTIONS 117 



(6) They can be dehydrated, cleared and mounted, or counter- 

 stained with eosin, orange-rubin, or Van-Gieson, and then 

 mounted. 



Hsematoxylin makes a good contrast stain for the tubercle and 

 the leprosy bacillus and for Actinomyces. 



Mayer's hsemalum (see section on the " Entamceba Mstolytica " ) 

 and Delafield's haematoxylin are also good hsematoxylin stains. 



(11) Ehrlich-Biondi triple stain : 



This is best bought ready for use. It is a good histological 

 stain for tissues and blood films, and actinomycosis stains well 

 by it. 



Stain for ten to sixty minutes, then treat with methylated spirit 

 until the section becomes greenish. Pass through absolute 

 alcohol, clear, and mount. 



(12) Leishman's stain : 



Like the Jenner, Wright, and other similar ones, a modification 

 of the Romanowsky stain, a double compound of eosin and 

 methylene blue. The solution will keep for some time, but is 

 best freshly prepared. Griibler's powder or Burroughs and Well- 

 come's soloid may be used, and is dissolved in pure methyl alcohol. 

 Failure frequently proceeds from the use of a so-called pure 

 methyl alcohol, which is not really so. (For method of using, 

 see "Malaria," Chapter XVIII.) 



(13) Giemsa stain : 



An eosin -azur mixture dissolved in pure glycerin and methyl 

 alcohol. Useful for blood -films, smears, etc., and has been much 

 used to demonstrate the spirochaetes in syphilitic material. (For 

 method of using, see " Syphilis " and " Malaria.") 



Safranin and acid fuchsin are also used as counter-stains. 

 Malachite green, neutral red, and rosein may be used for intra- 

 vitam staining of protozoa, etc. 



Eosin, orange-rubin, hsematoxylin, and picro-carmine keep 

 well in solution ; the remainder may or may not, and are best 

 used fairly fresh. All stains should be filtered before use, and 

 may be conveniently kept in bottles having a funnel fitted with a 

 filter-paper, so that they are always ready. Or smaller bottles 



