vi Foreword 



aid of isotopes as tracers. All of these problems require powers 

 of biochemical interpretation ; many of them demand also 

 new work in organic chemistry, both for the synthesis of the 

 specifically labelled precursors whose metabolic fate it is 

 desired to study, and for the stepwise degradation of the 

 biosynthetic product, so that the process of its formation can 

 be analysed. Again new methods of isolation of intermediary 

 metabolites may have to be devised. Thus the full develop- 

 ment of the isotope technique in this field can only be 

 achieved with the aid of concurrent advances in more con- 

 ventional chemical and biochemical methods. 



The collection of papers in the present volume, contributed 

 at an informal meeting by a number of leading workers, 

 affords as good an illustration as could be wished of the stage 

 of isotope research in biochemistry that has now been reached 

 by the process of development that has been outlined. The 

 Ciba Foundation are to be congratulated on performing a 

 useful service in assembling a number of contributions which 

 are not only of the greatest intrinsic interest but, in so far 

 as they indicate the potentialities of isotope research in 

 biochemistry, will serve as an inspiration for the further 

 cultivation of this productive field of work. 



