248 Biological Stains 



Giemsa stain available which gives results very much like the im- 

 ported product. 



Other uses of thiosin eosinates. Although thiazin eosinates are 

 specially known for their use as blood stains, they are coming more 

 and more to be employed for other purposes. Tolstoouhov (1928), 

 for instance, recommended a Romanovsky mixture as a tissue 

 stain, his solution proving stable because of the excess of methylene 

 blue present; he showed that such a mixture can produce a variety 

 of staining effects according to the reaction given to the solu- 

 tion by adding varying quantities of N/100 NaOH or HCl. The 

 same author (1929) later proposed a similar mixture for differ- 

 entiating one kind of bacteria from another. Churchman (1933) 

 has employed Wright stain for demonstrating bacterial capsules, 

 and Dutton (1928) to stain bacterial spores. Giemsa stain has 

 been used similarly, and also as a tissue stain. Lillie and Paster- 

 nack (1932, 1936) have, in fact, shown that various thiazin 

 eosinates can be used very effectively as a tissue stain; Lillie (1941) 

 has given in detail a technic for staining tissue with a specially 

 modified Wright stain following hematoxylin. His latest recom- 

 mendations (1944c) call for azure A, azure C or toluidine blue 

 salts of eosin Y or eosin B, with special preference for those of 

 eosin B which are stated to give deeper red staining of hemoglobin 

 and granules. 



PROCEDURES RECOMMENDED BY THE COMMISSION IN WHICH 

 THIAZIN EOSINATES ARE USED* 



*Under this heading are given references to procedures described in detail in 

 Staining Procedures, edited by Conn and Darrow (1943-4). 



Other Compound Stains 



Various other compounds of acid and basic dyes have been used 

 for special purposes. The basic dyes employed in these com- 

 pounds most commonly are perhaps methyl green and methylene 

 blue; but sometimes basic fuchsin, pyronin or rhodamine or even 

 a weak base like neutral red is used. Most common among the 

 acid dyes in these compounds are eosin, orange G and acid fuchsin ; 

 but certain others are occasionally employed. Picric acid forms a 

 few useful compound dyes, rosanilin picrate (i. e. the compound 



