DEHYDRATED CULTURE MEDIA 107 



granules and debris, or possible growth from extraneous organisms. It is neces- 

 sary to determine the presence of tubercle bacilli microscopically. Even though 

 the medium, inoculated with treated specimens, shows obvious contaminants, 

 a microscopic examination w^U often show that the tubercle bacilli have multi- 

 plied even in the presence of the contaminants. 



The medium may be prepared with or without glycerol. The addition of 

 glycerol enhances the growth of human strains of tubercle bacilli, and is not 

 required by bovine or avian strains. Glycerol may be added to the distilled water 

 at the time of rehydrating the medium. The use of Bacto-Glycerol is recom- 

 mended since it has been tested bacteriologically to insure freedom from toxic 

 principles and for suitability for use in this medium. 



To rehydrate the medium dissolve 1.3 grams Bacto-Dubos Broth Base in 

 180 ml. distilled water or 170 ml. distilled water containing 10 ml. Bacto- 

 Glycerol. Sterilize in the autoclave for 15 minutes at 15 pounds pressure 

 (121°C.). Cool to below 50°C. and add the contents of one tube Bacto-Dubos 

 Medium Albumin (20 ml.) or Bacto-Dubos Medium Serum (20 ml.) under 

 aseptic conditions. Mix thoroughly and distribute in 16-20 mm. diameter sterile 

 test tubes in 5-7 ml. amounts. Incubate for 24 hours to test sterility. The medium 

 is then ready for inoculation. 



One pound of Bacto-Dubos Broth Base will make 69.8 liters of medium. 



1 Am. Rev. Tuberculosis, 61:66:1950. » Personal Communications. 1947-48. 



2 J. Expl. Med., 83:409:1946. loProc. N.Y. State Assoc. Pub. Health Lab., 

 8 Am. Rev. Tuberculosis, 56:334:1947. 27:28:1947. 



* Proc. Soc. Exp. Biol. Med., 58:361:1945. 11 Am. Rev. Tuberculosis, 55:281:1947. 



sj. Exp. Med., 85:9:1947. "Am. Rev. Tuberculosis, 58:344:1948. 



•Proc. Soc. Exp. Biol. Med., 62:298:1946. ^^ j_ l^Jj^ Clin. Med., 32:837:1947. 



'J. Lab. Clin. Med., 32:842:1947. "J. Lab. Clin.. Med., 34:733:1949. 



8 Proc. Soc. Exp. Biol. Med., 65:210:1947. ^^ Am. J. Clin. Path., 20:1085:1950. 



BACTO 



DUBOS BROTH BASE (B435) 

 without Tween 80 



DEHYDRATED 



Bacto-Dubos Broth Base without Tween 80 has the same formula as Bacto- 

 Dubos Broth Base except Tween 80 has been omitted. In certain tests to deter- 

 mine the sensitivity of tubercle bacilli to various antibiotics or other bactericidal 

 agents it may be desirable to omit the Tween 80. There is a possibility that this 

 material present in the medium may influence the sensitivity of the tubercle 

 bacilli to the test substance. 



BACTO 



DUBOS OLEIC AGAR BASE (B373) 



DEHYDRATED 



Bacto-Gasitone 0.5 g, 



Bacto-Asparagine 1 g. 



Disodium Phosphate 2.5 g. 



Monopotassium Phosphate 1 g. 



Ferric Ammonium Citrate 50 mg. 



Magnesium Sulfate 10 mg. 



Calcium Chloride 0.5 mg. 



Zinc Sulfate 0.1 mg. 



Copper Sulfate 0.1 mg. 



Bacto-Agar 15 g. 



