DEHYDRATED CULTURE AIEDIA 211 



BACTO 



POLYMYXIN SEED AGAR (B463) 



DEHYDRATED 



Bacto-Casitone 17 g. 



Bacto-Soytone 3 g. 



Bacto-Dextrose 2.5 g. 



Sodium Chloride 5 g. 



Dipotassium Phosphate 2.5 g. 



Bacto-Agar 12 g. 



Tween 80 10 g. 



Bacto-Polymyxin Seed Agar is prepared according to the formula specified by 

 "The Compilation of Tests and Methods of Assay for Antibiotic Drugs,"^ 

 Federal Security Agency, Food and Drug Administration for the seed layer in the 

 cylinder assay of Polymyxin B. This medium has the same composition as Bacto- 

 Polymyxin Base Agar, as described above, except the agar content has been re- 

 duced to 1.2 per cent and contains 1.0 per cent Tween 80. In the assay of 

 Polymyxin B, Brucella bronchiseptica ATCG 4617 is the test organism using this 

 method. 



To rehydrate the medium, suspend 52 grams Bacto-Polymyxin Seed Agar in 

 1000 ml. distilled water and heat to boiling to dissolve the medium completely. 

 Distribute in tubes or flasks and sterilize in the autoclave for 15 minutes at 15 

 pounds pressure (121°C.). Final reaction of the medium will be pH 7.3. 



One pound of Bacto-Polymyxin Seed Agar will make 8.7 liters of medium. 



1 The Compilation of Tests and Methods of 

 Assay for Antibiotic Drugs, Federal Security 

 Agency, Food and Drug Administration. 



BACTO 



FLUID THIOGLYCOLLATE MEDIUM 



DEHYDRATED 



Fluid ThioglycoUate Medium is specified in the Compilation of Tests and 

 Methods of Assay for Antibiotic Drugs, Federal Security Agency, Food and Drug 

 Administration in the sterility testing of antibiotics. A complete discussion of this 

 medium is given on page 195. 



BACTO-PENASE 



Bacto-Penase and Bacto-Penase Concentrate are potent penicillinase prepara- 

 tions recommended for the inactivation of penicillin in the sterility testing of 

 penicillin or penicillin products. A complete discussion of these products is 

 given on page 283 and 284. 



