SOME ASPECTS OF VITAMIN AND GROWTH 

 FACTOR RESEARCH 



ESMOND E. SNELL, Biochemical Institute, University of Texas, 



Austin. Texas 



The fifteen years since 1940 have been marked by an un- 

 precedented rate of increase in our knowledge of the nature and 

 metabolic role of vitamins and similar growth factors. The 

 perfection of chromatographic methods of purification, together 

 with the partial substitution of rapid microbiological assays for 

 the more tedious bioassay procedures with higher animals, has 

 contributed much to this increase. Detailed accounts of the 

 current status of knowledge of the vitamins have appeared 

 (54,57,81); here no such account will be attempted. Rather 

 shall we be content to emphasize a few aspects of recent nutri- 

 tional research (and consequently slur others) and their implica- 

 tions for future progress in this field. 



Microbiological Techniques in Vitamin Research 



Some fourteen years ago Peterson (43) and Williams (80) 

 emphasized the growing importance of microorganisms as tools 

 in nutritional research by pointing out that work with micro- 

 organisms had resulted in discovery of certain of the B-vitamins 

 (pantothenic acid, biotin) and in the first demonstration of the 



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