STANDARDIZATION OF STAINS 



15 



Fast green FCF 



Fuchsin, acid 



Fuchsin, basic 



Giemsa stain 



Hematoxylin 



Indigo carmine 



Janus green B 



•Tenner's stain 



Light green, S.F., yellowish 



Malachite green 



Martins yellow 



Methyl green 



Methyl orange 



Methyl violet 2B 



Methylene blue chloride 



Methylene blue thiocyanate 



Methylene violet 



Neutral red 



Nigrosin 



Nile blue A 



Orange G 



Orange II 



Orcein 



Phloxine 



Pyronin 



Resazurin 



Rose bengal 



Safranin O 



Sudan III 



Sudan IV 



Tetrachrome stain (MacNeal) 



Thionin 



Toluidine blue O 



Wright's stain 



Eight ccmpanies in the United States are now submitting their stains to the 

 Commission for certification before putting them on the market. It must be 

 reahzed, however, that no one of these concerns necessarily manufactures all 

 the stains which it thus submits ; but in the case of any stain which is manufac- 

 tured elsewhere, the company takes responsibility for its performance as a bio- 

 logical stain, on the basis of tests made to show its adequacy, and in many in- 

 stances carries out a certain degree of purification or other processing before 

 putting the stain on the market. One of these companies puts on the market 

 every stain now on the certification list. Two other companies submit samples 

 of over half the stains thus listed, while the other companies merely request 

 certification of one or two dyes in which they specialize. No dyes have yet 

 been certified by the Stain Commission submitted by any foreign concern 

 except for one located in Montreal. Cooperation among the Americas is 

 increasing (Conn, H. J., Stain Techn., 1942, 17, 5-6). 



In several recent editions of the National Formulary, published by the Ameri- 

 can Pharmaceutical Association, a section has been included in which formulae 

 of staining solutions are given. Originally there was no agreement between 

 these formulae and the ones recommended by the Stain Commission. Begin- 

 ning in 1937, however, it was decided that the National Formulary Committee 

 and the Biological Stain Commission should cooperate in this matter. Accord- 

 ingly, the chairman of the latter was made a member of the former and a member 

 of the National Formulary was put on the Executive Committee of the Com- 

 mission. This interlocking membership is assurance that the work of preparing 

 staining formulae for the next edition of the National Formulary is being carried 

 on in close cooperation with the Stain Commission. This cooperation has al- 

 ready resulted in two important steps: 



1. Specifications of the most important stains now on the certification basis 

 have been drawn up for the National Formulary (1942). These specifications 

 are partly chemical and spectrophotometric, but also contain detailed state- 



