98 DIFGO MANUAL 



BACTO 



STOCK CULTURE AGAR (B54) 



DEHYDRATED 



Beef Heart, Infusion from 500 g. 



Proteose Peptone, Difco 10 g. 



Bacto-Gelatin 10 g. 



Bacto-Dextrose 0.5 g. 



Bacto-Isoelectric Casein 5 g. 



Disodium Phosphate 4 g. 



Sodium Citrate 3 g. 



Bacto-Agar 7.5 g. 



Bacto-Stock Culture Agar is recommended for the maintenance of cultures of 

 streptococci and other organisms. It is a soft, almost semisolid medium. 



Ayers and Johnson^ described a medium that gave luxuriant growth and long 

 life of streptococci. Their medium was developed from a formula originally 

 given them by Supplee. The success of their medium probably lies in the fact 

 that the medium has a semisolid consistency, contains casein, is well buffered and 

 contains a small quantity of dextrose which serves as a readily available source 

 of energy. They reported that pathogenic streptococci remained viable for at least 

 four months at room temperature (24°G.) in their medium. Organisms other 

 than streptococci, such as pneumococci, human tubercle bacilli and others grew 

 well on their Stock Culture Agar. 



Bacto-Stock Culture Agar is prepared to duplicate the medium described by 

 Ayers and Johnson. This medium, likewise, will support luxuriant growth of 

 many pathogenic bacteria and preserve their viability over a long period of time. 



Bacto-Cooked Meat Medium, as discussed on page 85, is also recommended 

 as a medium for carrying cultures in stock. For carrying cultures of gonococcus, 

 meningococcus, and other organisms not capable of splitting starch, the infusion 

 free Bacto-Dextrose Starch Agar, in half concentration, is recommended as dis- 

 cussed on page 125. 



To rehydrate the medium, suspend 50 grams of Bacto-Stock Culture Agar in 

 1000 ml. of cold distilled water and heat to boiling to dissolve the medium com- 

 pletely. Distribute in tubes and sterilize in the autoclave for 15 minutes at 15 

 pounds pressure (121°G.). The final reaction of the medium will be pH 7.5. 



One pound of Bacto-Stock Culture Agar will make 9 liters of medium. 



■ij. Bact., 9:111:1924, 



BACTO 



LIVER VEAL AGAR (B59) 



DEHYDRATED 



Bacto-Liver, Infusion from 50 g. 



Veal, Infusion from 500 g. 



Proteose Peptone, Difco 20 g. 



Neopeptone, Difco 1.3 g. 



Bacto-Tryptone 1.3 g. 



Bacto-Dextrose 5 g. 



Soluble Starch, Difco _ 10 g. 



Bacto-Isoelectric Casein 2 g. 



Sodium Chloride 5 g. 



Sodium Nitrate 2 g. 



Bacto-Gelatin 20 g. 



Bacto-Agar 15 g. 



