LEAFLET VI 

 FURTHER BIOCHEMICAL METHODS 



Introduction 



Leaflet V dealing with routine tests for the Descriptive Chart 

 describes certain of the simpler biochemical tests used quite generally 

 in the study of bacteria. There are, however, a considerable number of 

 biochemical tests which are in fairly common use in the pure culture 

 study of bacteria but which are not included in Leaflet V for one or 

 the other of two reasons: they either apply only to certain special 

 groups of bacteria or they involve such intensive chemical study that 

 they cannot easily be used in routine work. The methods given in this 

 Leaflet, therefore, are to be used primarily in the study of special 

 groups of bacteria after a preliminary survey has established most of 

 their general morphological and physiological characteristics. In such 

 cases it is very often desired to make a more careful physiological 

 study of a few strains, and the routine tests given in Leaflet V or in 

 previous editions of Leaflet VI are entirely inadequate for any de- 

 tailed biochemical investigations. 



The sixth (1935) edition of Leaflet VI was the first to deal with any 

 but routine biochemical tests, and accordingly its title was then 

 changed to show the new field covered by it. The first editions of the 

 Leaflet under its new title are necessarily incomplete. The object of this 

 Manual has always been to list methods that have actually been used 

 by members of the Committee and have been found practical in pure 

 culture study of bacteria. Inasmuch as the new field now covered by 

 Leaflet VI is a very broad one, the present Committee members have 

 not had experience with procedures in all the lines that should be in- 

 cluded. Accordingly, it is planned to make the first editions quite 

 brief, with the intention of revising this text and adding new material 

 with each successive edition until the field is more adequately covered. 

 Assistance from users loill he greatly appreciated in making suggestions 

 as to what should be covered in future editions. It is hoped that the 

 present edition will be of value in pointing the way to methods for those 

 who are confused by the multiplicity of procedures in the literature. 



In making a physiological study of any kind of bacteria, special 

 consideration should be given to the question of variation as discussed 

 at the beginning of Leaflet V. Strain variations, in fact, are more likely 

 to affect biochemical reactions than matters of morphology. It is, ac- 

 cordingly, important that no conclusions be based upon single deter- 

 minations, nor even upon several determinations when all are made 

 upon a single strain. It cannot be overemphasized that a physiological 

 study of any type of bacteria should always be based upon repeated 



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