DEHYDRATED CULTURE MEDIA 



115 



that a few of the numerous samples of Bacto-Tryptose which had been in his 

 laboratory exhibited some toxicity for certain Brucella abortus strains used in his 

 laboratory. The particular samples of Bacto-Tryptose possessing this character- 

 istic had absorbed moisture and had undergone chemical change. Schuhardt^^ 

 in a discussion of this observation stated that "the ease of neutralization of this 

 toxic factor by blood, serum, agar and other substances tends to make the prac- 

 tical significance of the toxicity relatively minor. We probably would not have 

 encountered it had we not been doing extensive tests on the in vitro effect of 

 sulfonamides on Brucella using decimal dilution inocula". The high productivity 

 of Bacto-Tryptose Agar and Bacto-Tryptose used clinically for the isolation and 

 cultivation of Brucella attests to its value for the primary cultivation of Brucella 

 as well as other fastidious organisms. 



To rehydrate the medium, suspend 41 grams of Bacto-Tryptose Agar in 1000 

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

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

 at 15 pounds pressure (121°G.). The final reaction of the medium will be 

 pH7.2. 



Since most microorganisms prefer a fresh medium with a moist surface, it is 

 recommended that Bacto-l'ryptose Agar be prepared as required, or melted and 

 re-solidified just prior to use. 



One pound of Bacto-Tryptose Agar will make 1 1 liters of medium. 



1 Standard Methods for the Examination 

 of Dairy Products, 9th Edition: 149: 1948. 



2 Diagnostic Procedures and Reagents, 

 3rd Edition: 246: 1950. 



3 Tech. Bull., 49 Mich. Exp. Sta., 1920. 

 * J. Infectious Diseases, 40:353:1937. 



s Huddleson : Brucellosis in Man and Animals, 



«J. Am. Med. Assoc, 109:1971:1937. 



'Am. J. Clin. Path., 5:313:1935- 



«J. Bact., 37:153:1939. , ^ 



eProc. Soc. Expl. Biol. Med., 64:114:1947- 

 "^Am. J. Clin. Path., 19:697:1949- 

 11 Tech. Bull. 100, Mich. Exp. Sta., 1929. 

 "Am. J. Pub. Health, 21:491:1931- 

 "Am. J. Clin. Path., 81:894:1951. 



J. Infectious Diseases, 

 Monograph No. 



3:633:1906. 

 Rockefeller Inst. Med. 

 Research, 1919. 

 "J. Path. Bact., 49:83:1939- 

 1'' Am. J. Clin. Path., 9:1939, Tech., Suppl. 



3:20:1939. 

 18 Am. J. Vet. Res., 11:252:1950. 

 ^ J. Immunol., 65:163:1950. 



20 Public Health Reports, 66:44:1951. 



21 J. Bact., 52:453:1946. 



22 J. Bact.. 55:471:1948- 



23 J. Bact., 59:443:1950. 



2* J. Am. Vet. Med. Assoc, 118:242:1951. 



25 J. Bact., 57:1:1949- 



28 Personal Communication, 1949- 



BACTO 



TRYPTOSE BLOOD AGAR BASE (B232) 



DEHYDRATED 



Bacto-Tryptose 10 g. 



Bacto-Beef Extract 3 g. 



Sodium Chloride 5 g. 



Bacto-Agar 15 g. 



Bacto-Tryptose Blood Agar Base is a nutritious, infusion-free peptone medium 

 designed especially for use as a base in the preparation of Blood Agar. Blood 

 Agar prepared with this base supports excellent growth of many fastidious 

 organisms and also gives typical clear-cut hemolytic reactions. Bacto-Tryptose 

 Blood Agar Base, without added blood, may be recommended as a Nutrient 

 Agar for general routine culture purposes. 



Investigations of the nutritive properties of Bacto-Tryptose demonstrated 

 that culture media prepared with this peptone were superior to the meat in- 

 fusion peptone media previously used for the cultivation of Brucella, strepto- 

 cocci, pneumococci, meningococci and other fastidious pathogenic bacteria. The 

 use of Bacto-Tryptose in place of infusion in Blood Agar Base yields a medium 



