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DIFCO MANUAL 



DIFFERENTIAL MEDIA 



Many media have been designed for the separation or differentiation of closely 

 related organisms or groups of organisms. The differentiation by means of cul- 

 tural characteristics is of decided value and importance especially where mor- 

 phology and other biological characteristics are almost identical. The following 

 dehydrated culture media represent a group of differential media, some of which 

 are not selective and depend on cultural characteristics for differentiation, while 

 others are selective and in addition show colonial differences between organisms. 

 The isolation of members of the enteric group by means of differential media has 

 been a routine procedure for many years. More recently differential media have 

 been described for the isolation of other groups of organisms such as diphtheria, 

 staphylococci and streptococci. Differential media for these isolation purposes are 

 discussed in this section. 



Suggested Schema for the Examination of Stools or Other Material for Bacterial 

 Incitants of Enteric Disease 



Specimen 



Enrichment Bacto-Tetrathionate Broth 

 Bocto-Selenite Broth 



Primary Ploting Medio Bocto-MocConkey Agar 



Bacto-Desoxycholote Agar 

 Bacto-S S Agar 



Bocto-Desoxychoiote Citrate Agar 

 Bocto-Bismuth Sulfite Agar 



Bacto-Brilliant Green Agar (only for Salmoneilo other than 

 S. typhoso). 



Purification Plate Bacto-MacConkey Agar 



Differential Media 



Primary Bacto-Russeil Double Sugar Agar 



Bacto-Krumwiede Triple Sugar Agar 

 Bacto-Triple Sugar Iron Agar 

 Bocto-Kligler Iron Agar 

 Bacto-Friewer Shaughnessy Medium 



Plote for Purity Bocto-MocConkey Agar 



Secondory Bacto-Purple Broth Base-fKey Sugars 

 Bacto-S I M Medium 

 Bacto-Urea Agar or Bacto-Urea Broth 

 Bocto-Simmons Citrate Agar 

 Bacto- Phenol Red Tartrate Agar 



Serological Identification 



