CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



669 



(18) Filter thru absorbent cotton and 

 paper until clear. 



(19) Mix the filtrate with an equal 

 amount of water. 



(20) Solidify (19) by the addition of 1.5% 

 agar in the usual manner. 



Sterilization: Sterilize at 15 pounds pres- 

 sure for 30 minutes. 



Use: General culture medium. 



Reference : Park, Williams and Krumwiede 

 (1924 p. 119). 



2069. Gordon and Hines' Trypagar 



Constituents : 



1. Water 



2. Pea flour 100.0 g. 



3. NaCl 100.0 g. 



4. Heart bullock 500.0 g. 



5. Agar 20.0 g. 



6. CaCl2 0.125 g. 



Preparation : 



(1) Add a liter of water to a 100.0 g. of 

 pea flour and 100.0 g. NaCl. 



(2) Mix thoroly and steam for 30 min- 

 utes, stirring occasionally. 



(3) Allow to settle and filter the super- 

 natant liquid. 



(4) Add 1000.0 cc. of water to 500.0 g. of 

 finely chopped bullock heart and 

 make slightly alkaline to litmus by 

 the addition of 20.0% KOH solution. 



(5) Heat (4) slowly at 75 to 80°C. for 

 5 minutes. 



(6) Cool to 37°C. and add 1.0% liquor 

 trypsinae (Allen and Hanbury's) 

 and incubate at 37°C. for two and 

 one-half to three hours. 



(7) Test for peptone using the Biuret 

 test. 



(8) Render slightly acid to litmus by the 

 addition of glacial acetic acid and 

 boil for 15 minutes. 



(9) Leave over night in a cool place and 

 siphon off the clear liquid in the 

 morning. 



(10) Make faintly alkaline to litmus. 



(11) Weigh out 20.0 g. agar and cut in 

 fine pieces with a scissors. 



(12) Wash (11) with water and drain 

 thoroly. Add a sufficient quantity 

 of water to cover the agar and add 

 2.5 g. of glacial acetic acid per liter 

 of water. 



(13) Mix acid and agar thoroly and leave 

 for 15 minutes. 



(14) Pour off the water and wash thoroly 

 until the agar is free from acetic 

 acid. 



(15) Add the agar obtained from (14) to 

 1000.0 cc. of (10). 



(16) Add 0.125 g. CaCU. 



(17) Autoclave for 45 minutes to dissolve 

 the agar. 



(IS) Neutralize to phenolphthalein by the 

 addition of N/10 KOH while hot. 



(19) Cool to 60°C. and add the white of 

 2 eggs beaten up with the crushed 

 shells. 



(20) Autoclave again at 118°C. for 

 75 minutes or heat in the steamer for 

 2 hours. 



(21) Filter. 



(22) Add 2.0% of sterile (3). 



(23) Distribute as desired. 

 Sterilization: Sterilize (23) in the ordinary 



way. 

 Use: Cultivation of meningococci. Wood 



used a similar medium for the cultivation 



of diphtheria bacilli. 

 Variants: Wood added 0.3 cc. of a sterile 



1.0% telluric acid solution to 10.0 cc. of 



the agar for the cultivation of diphtheria 



bacilli. 

 Reference: Gordon and Hines (1916 



p. 682), Wood (1921 p. 562). 



2070. Duval and Harris' Tryptic Digest 

 Agar 



Constituents: 



1. Water 1000.0 cc. 



2. Agar (3.0%) 30.0 g. 



3. Tryptic Digest Solution, . . . 1000.0 cc. 

 Preparation : 



(1) Prepare a 3.0% agar solution in water. 



(2) Tube. 



(3) Melt sterile tube of (2) and cool to 

 45°C. 



(4) Mix equal parts of the sterile agar 

 with Duval and Harris' Tryptic Di- 

 gest Solution (See medium 1134). 



(5) Slant and cool. 



Sterilization: Method of sterilization of 

 agar solution not given. The Tryptic 

 Digest Solution is sterilized by filtering 

 thru a Berkefeld filter. 



Use: Cultivation of leprosy bacillus. 



