288 DIFCO MANUAL 



DEHYDRATED MEATS 

 FOR INFUSIONS 



BAGTO-BEEF (B131) 



Bacto-Beef is desiccated powdered fresh lean beef. It is prepared especially for 

 use in making beef infusion media. Large quantities of beef are processed at one 

 time in order to secure a uniform and homogenous product. The nutritive 

 qualities of the fresh beef are retained in Bacto-Beef and may be preserved in 

 the infusions prepared from it. Media prepared from Bacto-Beef are superior to 

 beef extract media and are equal to infusion media made from market beef. 



The equivalent of 500 grams of fresh lean beef is secured from 100 grams of 

 Bacto-Beef. An excellent infusion, however, can be prepared by using 50 grams 

 of Bacto-Beef per 1000 ml. of distilled water. This mixture is infused at 50° C. 

 for one hour. It is then heated to boiling for a few minutes to coagulate some of 

 the proteins and is filtered. Peptone and the other ingredients of the medium are 

 then added to the filtrate. After adjustment of the reaction to pH 7.5-7.8 and 

 subsequent boiling for a few minutes there will be a further coagulation which 

 should be removed by filtration before the medium is sterilized. 



Infusion media prepared from Bacto-Beef have been recommended for use 

 in the microbial examination of butter.^ Herrold- has also used an infusion from 

 Bacto-Beef in preparing Blood Agar for primary cultivation of the gonococcus. 

 Bacto-Beef is used in the National Formulary^ specifications in determining the 

 proteolytic activity of papain. 



1 J. Dairy Science, 16:289: 1933. 3 National Formulary, Eighth Edition:37i : 1946. 



2 J. Infectious Diseases, 42:79:1928. 



BAGTO-BEEF HEART FOR INFUSIONS (B132) 



Bacto-Beef Heart for Infusions is prepared from fresh beef heart tissue and 

 is particularly recommended for preparing heart infusion media. Bacto-Beef 

 Heart for Infusions is processed from large quantities of raw material, retaining 

 all the nutritive and growth-stimulating properties of the fresh tissues. 



One hundred grams of Bacto-Beef Heart for Infusions are the equivalent of 

 500 grams of fresh heart tissue. Generally, excellent infusions can be prepared 

 using 50 grams of Bacto-Beef Heart for Infusions per 1000 ml. of distilled water. 

 For best results infuse at 50° C. for 1 hour, then heat to boiling for a few minutes 

 to coagulate some of the proteins, and filter. Peptone and the other ingredients 

 of the medium should then be added to the filtrate, the reaction adjusted to 

 pH 7.5-7.8, and the medium boiled and filtered before sterilizing. 



Bacto-Beef Heart for Infusions is recommended for the preparation of St. 

 John's Medium^ for the cultivation of Endamoeba histolytica by Brown in 

 '"Diagnostic Procedures and Reagents"- of the American Public Health Associa- 

 tion. Morton, Smith and Leberman^ used Bacto-Beef Heart for Infusions in a 

 medium recommended for the cultivation and isolation of Pleuropneumonia-like 

 organisms. 



Bacto-Beef Heart for Infusions is not to be confused with Bacto-Beef Heart 

 (for antigens) as discussed on page 315. The latter product is prepared for an. 



