CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



623 



30.0 g. 

 10.0 g. 



5. Agar 



6. Gum tragacanth 



Preparation : 



(1) Macerate 500.0 g. of finely chopped 

 beef in 1200.0 cc. water at 37° for 

 5 or 6 hours. 



(2) Press thru a linen cloth. 



(3) Add 3 and 4 and boil. 



(4) Filter on a wet filter paper. 



(5) Neutralize with soda using litmus 

 and then add 7.0 cc. of normal soda 

 solution to a liter of medium. 



(6) Pulverize the gum tragacanth in a 

 large dry glass mortar by means of 

 a pestile. 



(7) Carefully mix (6) with (5), so as not 

 to obtain lumps or a gum. Mix the 

 bouillon thoroly after each addi- 

 tion of (6). 



(8) Add the mixture to a 1.5 or 2 liter 

 flask and add the agar. 



(9) Heat at 115° for 30 minutes to dis- 

 solve the agar. 



(10) Filter while hot. 



(11) Distribute. 



Sterilization: Sterilize at 115° for 300 



minutes. 

 Use: Isolation of gonococcus. Cultivation 



of pasteurella and salmonella. 

 Variants : 



(a) To prepare a semi-solid agar use only 

 3.0 g. agar instead of 30.0 g. 



(b) van Saceghem recommended the use 

 of gum arable instead of gum traga- 

 canth in this medium. When gum 

 arable is used he obtained vigorous 

 growth of pasteurella and salmonella 

 also. 



References: Costa and Boyer (1922 p. 857), 

 van Saceghem (1923 p. 968). 



1949. Capaldi's Egg Yolk Agar 



Constituents: 



1. Nutrient agar. 



2. Egg yolk. 

 Preparation : 



(1) Break an egg, separate the white 

 from the yolk and place the yolk in a 

 sterile Petri dish. 



(2) Prepare nutrient agar. 



(3) Place a glowing glass rod on a spot 

 on the covering of the egg yolk. 

 (This sterilizes the covering of the 

 naturally sterile yolk.) 



(4) Melt sterilized agar and cool to 45°C. 



(5) Remove 3-4 loops (exact amount not 

 given) of egg yolk thru the portion 

 of covering of the yolk that had been 

 sterilized and add to tube of (4). 



(6) Mix thoroly and plate or slant. 

 Sterilization: Method not given. 



Use: Culture and diagnosis of diphtheria. 



Also used to cultivate tubercle bacilli. 

 Variants: Bezan5on prepared a similar 



medium as follows: 



(1) Place an egg in boiling water for 

 several minutes. This coagulates the 

 white. 



(2) Sterilize one end of the shell and make 

 a small opening into the egg. 



(3) Remove the yolk from the egg by 

 asparating with a sterile pipette. 



(4) Add the yolk (amount not specified) 

 to sterile melted agar. 



(5) Mix thoroly. 



(6) Slant. 



References: Capaldi (1896 p. 801), Heine- 

 mann (1905 p. 130), Tanner (1919 p. 58), 

 Bezan9on(1920p. 121). 



1949a. Tulloch's Ox Heart Infusion Pea 

 Flour Agar 



Constituents : 



1. Water •• 600.0 cc. 



2. Peptone (Bacto) 10.0 g 



3.KC1 0.38g 



4. CaClj 0.44 g 



5. NaHCOs 018g 



6. Na-iHPO 4 (crystalline) 5.0 g 



7. Agar 25.0 g 



8. Heart, ox 500.0 g. 



9. Pea extract 

 Preparation : 



(1) Dissolve 2, 3, 4, 5 and 6 in 1 by steam- 

 ing (500.0 cc. of Douglas' trypsinized 

 broth and 100.0 cc. of Cole's trypa- 

 mine may be used instead of 600.0 cc. 

 of Bacto peptone solution). 



(2) Soften 25.0 g. of fiber agar by soaking 

 in 0.25% acetic acid for 15 minutes. 

 Wash the agar free from acid and 

 squeeze thru lint to get rid of as 

 much water as possible. 



(3) Heat (1) and (2) on a water bath for 

 20 to 30 minutes. Then boil over a 

 free flame for 15 minutes to complete 

 the solution of the agar. 



(4) Adjust to pH 7.6 and keep at 56°C. 



