XXX STANDARDIZATION OF STAINS 



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

 ments as to how the stains should be tested as to their behavior for biological 

 purposes and state the results to be expected from these tests. In every case 

 these specifications have been made to harmonize with the tests as actually per- 

 formed by the Stain Commission. 



2. The formulae given in the National Formulary, in "Biological Stains" and 

 in the "Manual of Methods for the Pure Culture of Bacteria," published by the 

 Society of American Bacteriologists, have been compared and critically studied 

 with the object of making them identical in all three. 



The years since the second World War have seen more progress in stain 

 standardization than during any preceding similar period. Dr. E. H. Stotz, 

 Biochemist, of University of Rochester Medical School, has been made an officer 

 of the Stain Commission and is now in charge of its research and assay labora- 

 tory at Rochester, N. Y. This laboratory is making a comprehensive survey of 

 nearly every stain sample that has ever been submitted for certification, making 

 a systematic comparison between their physical and chemical characteristics 

 (notably spectrophotometric) and behavior in staining. If it is ever going to be 

 possible to draw up specifications that correlate with staining properties, such 

 a survey should furnish the necessary data. 



