198 DIFGO -MANUAL 



BACTO 



N.I.H. THIOGLYGOLLATE BROTH (B257) 



DEHYDRATED 



Bacto-Yeast Extract 5 g 



Bacto-Casitone 15 g 



Bacto-Dextrose 1 g 



Sodium Chloride 2.5 g 



/-Cystine, Difco 0.05 g 



Thioglycollic Acid 0.3 ml 



Bacto-N.I.H. Thioglycollate Broth is prepared according to the formula for 

 Broth Medium for sterility tests as specified by the National Institute of Health.^ 

 This medium may be substituted for Bacto-Fluid Thioglycollate Medium in the 

 sterility testing of certain biological products that are turbid or otherwise cannot 

 be cultured satisfactorily in Fluid Thioglycollate Medium because of its viscosity. 

 Bacto-N.I.H. Thioglycollate Broth conforms to the specifications for the alternate 

 fluid medium for sterility tests as given in the U. S. Pharmacopeia^ and the 

 National formulary.^ 



In testing solutions for sterility, Bacto-N.I.H. Thioglycollate Broth should be 

 used in Smith fermentation tubes and be heated in boiling water or on a steam 

 bath just prior to use to drive off dissolved oxygen. When testing the sterility 

 of solutions containing preservatives, the preservative must be inactivated, or 

 sufficient medium used to dilute the inoculum beyond the bacteriostatic limits of 

 the preservative. Bacto-N.I.H. Thioglycollate Broth contains thioglycollate to 

 neutralize the bacteriostatic effect of mercurial preser\'atives. The table on page 

 197 under Bacto-Fluid Thioglycollate Medium indicates minimum quantities of 

 medium to use in testing the sterility of solutions containing other preservatives. 



To rehydrate the medium, suspend 24 grams Bacto-N.I.H. Thioglycollate 

 Broth in 1000 ml. cold distilled water and heat to boiling to dissolve the medium 

 completely. Distribute in Smith fermentation tubes and sterilize in the auto- 

 clave for 18-20 minutes at 15-17 pounds pressure (121-123°C.). The final 

 reaction of the medium will be pH 7.1. 



One pound of Bacto-N.I.H. Thioglycollate Broth will make 18.9 liters of 

 medium. 



1 National Institute of Health Circular: Culture ^ Pharmacopeia of the United States, XIV Re- 

 Media for the Sterility Test, and Revision, vision: 759:i95o. 

 Feb. 5, 1946. s >Tational Formulary, 9th Edition: 769: 1950. 



BACTO 



N.I.H. AGAR MEDIUM (B258) 



DEHYDRATED 



Bacto-Yeast Extract 5 g. 



Bacto-Casitone 15 g. 



Bacto-Dextrose 1 g. 



Sodium Chloride 2.5 g. 



/-Cystine, Difco 0.05 g. 



Bacto-Agar 15 g. 



Bacto-N.I.H. Agar Medium is prepared according to the formula for the 

 Agar Medium as specified by the National Institute of Health Circular for Cul- 

 ture Media for Sterility Test.^ It is recommended for use when a solid agar 

 medium is needed for the maintenance of cultures isolated in connection with the 

 sterility testing of biological products. It may also be used as a solid medium for 

 sterility testing. 



