PREFACE 



amounts of material rapidly, selectively, and even quantita- 

 tively, gave wings to biochemistry. In turn, this led to the 

 intensive exploitation and development of a large variety of 

 adsorption and partition procedures which almost overnight 

 made it not only possible, but even relatively simple to separate 

 and isolate constituents of any mixture, regardless of how similar 

 the constituents may happen to be. Isolation ceased to be a 

 roadblock or a major difficulty in biochemical investigation. 



The spectrophotometer occupies a preeminent position 

 among the instruments which have facilitated the dramatic 

 advances in methodology. This was of course not a new 

 physical tool, but until some ten years ago it was a highly ex- 

 pensive, custom-built apparatus available only to relatively few 

 laboratories with considerable resources. With the advent of 

 the mass-produced spectrophotometer, the universal application 

 of spectrophotometric techniques to biochemical problems 

 became possible. It is no exaggeration to say that spectro- 

 photometry has increased manyfold the forward rate of progress 

 of biochemistry. 



Other tools and techniques have played an equally im- 

 portant role in the revolution of biochemical methodology 

 during the past decade. The isotope technique with its count- 

 less ramifications and variations and the mass-produced ultra- 

 centrifuge and electrophoresis apparatus were also very domi- 

 nant factors in the over-all picture. 



With such a plethora of powerful tools available, structural 

 problems that had long resisted solution were dusted off the shelf 

 and liquidated in record time. Nucleotides, nucleic acid, 

 polysaccharides, lipides, polypeptides, and even some proteins of 

 low molecular weight were no match for the many and incisive 

 methods which were brought to bear in the elucidation of 

 stucture. Even efforts at synthesis took a new lease of life now 

 that effective methods were available for separation of similar 

 reaction products, or isomers, as in the case of nucleotides. It 

 was a triumph of methodology to ferret out the exact structural 

 formula of insulin and to accomplish the synthesis of flavin 



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