STANDARDIZATION OF STAINS 



In the use of stains one encounters a multitude of names, many of which are 

 sj'nonyms, and it is difficult to be sure of their meaning. Two comprehensive 

 dye indexes have been published. One, "Schultz' Farbstofftabellen", is now in 

 its 7th edition (1928 to 1934) but confusion is created by the fact that the index 

 numbers of the dyes given in it do not correspond to those in the earlier editions. 

 The other, the "Colour Index of the Society of Dyers and Colourists", was edited 

 by F. M. Rowe and published in 1924. It was followed in 1928 by a supplement, 

 but there has been no second edition. This Colour Index gives (1) the com- 

 mercial name, or much more frequently names for there are so many synonyms ; 

 (2) the formula, (3) the preparation, (4) the discoverer and (5) the properties of 

 a vast assemblage of dyes. It is the standard of reference in the United States 

 and other English-speaking countries. When one wishes to be specific it is 

 customary to list after the dye used its colour index number, for example vital 

 red, C. I. No. 456. 



The most recent Year Book of the American Association of Textile Chemusts 

 and Colorists, New York: Hawes Publishing Co. 1945, 743 pp. is often of as- 

 sistance. It provides an alphabetical list of over 6,000 American made dyes with 

 classification, manufacturer and Colour Index Number if any. A listing of 

 American made Dyes arranged by Colour Index Numbers is also useful. For 

 example, if one is interested in Orange II CI, 151 it will be seen that this is avail- 

 able under 26 names from 12 difTerent makers. In another place the foreign 

 prototype names of dyes without Colour Index numbers are listed alphabetically 

 with the corresponding American dyes and their manufacturers so that the 

 available American substitutes for foreign dyes can be found. This Year Book 

 is unfortunately often lacking in medical school libraries but it is usually on 

 hand in the better Public Libraries like that of St. Louis. 



Much aid is given to investigators by the Biological Stain Commission and 

 particularly by its distinguished Founder, Dr. H. J. Conn. This commission 

 is concerned with the inspection and standardization of stains, not with their 

 manufacture as is sometimes supposed. It was found in 1920, while the post- 

 war embargo on dyes was still in effect, that American scientists v/ere being sup- 

 plied with dyes from three or four different stain companies and that their 

 products were not sufficiently uniform to be reliable. Accordingly, through the 

 cooperation of the National Research Council and of several national scientific 

 societies, the Commission on Standardization of Biological Stains (now the 

 Biological Stain Commission) was established. The Commission is now an 

 independent organization but includes in its membership representatives of 

 eight societies with which it cooperates. The work of the Commission is two- 

 fold. First, by cooperation of biologists and chemists it gathers information 

 concerning the nature of dyes as related to their use in microscopic technique; 



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