CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 697 



over a free flame. In order to 

 prevent loss of water during boiling 

 place a lid over the container or 

 steam for 3 to 3.5 hours in a steamer. 

 The casein coagulates slowly. 



(8) Press thru four folds of linen cloth. 



(9) The reaction of the fluid is slightly 

 acid. 



(10) Pour into a tall glass cylinder and 

 place in a warm thermostat. 



(11) After about 20 or 30 minutes remove 

 the yellow top layer containing the 

 fat by means of a spoon. 



(12) Heat the fat-free portion to boiling 

 and add 1.0% of the filtrate from (5). 



(13) Add soda to neutralize the reaction. 



(14) Add 0.5% NaCl if desired. 



(15) Filter until clear thru a paper in a 

 hot water funnel. 



Sterilization: Not specified. 



Use: Cultivation of pathogenic organisms. 



Reference: Raskin (1887 p. 359). 



2159. Reinsch's Alkaline Milk Agar 



Constituents : 



1. Water 100.0 cc. 



2. Agar 3.0 to 4.0 g. 



3. Milk 500.0 cc. 



4. NaOH 1.0 g. 



Preparation: 



(1) Soak 3.0 to 4.0 g. of powdered agar in 

 100.0 cc. water for 24 hours. 



(2) Add egg white and boil for 3 to 4 

 hours in a steamer. 



(3) Filter. 



(4) Place 500.0 cc. of fresh cow milk in a 

 separatory funnel and add 1.0 g. 

 NaOH (2.5 cc. solution of 400.0 g. 

 NaOH in a liter). 



(5) Shake well and allow to stand at 

 about 18°C. for 48 hours. 



(6) Remove the nearly transparent milk 

 from the bottom of the funnel and 

 add it to a second separatory funnel. 



(7) Add 250.0 cc. ether and shake well. 



(8) Allow to stand for 48 hours. 



(9) Place the opalescent liquid now in a 

 large sterile flask, plug with cotton 

 and heat to 50°C. 



(10) Place under the receiver of a water 

 suction pump for 3 or 4 hours until 

 all the ether is evaporated. 



(11) Mix 1 part of (3) with 3 parts of (10) 

 at about 50'"C. 



(12) Distribute into sterile test tubes. 



(13) Incubate to test sterility. 

 Sterilization: Sterilization of (3) not given. 

 Use: Cultivation of typhoid bacilli and 



others. The author reported that the 

 agar was light yellow, transparent and 

 slightly opalescent. 

 Variants: The author prepared a slightly 

 darker medium as follows: 



(1) Place 500.0 cc. of fresh cow milk in a 

 separatory funnel and add 1.0 g. 

 NaOH (2.5 cc. solution of 400.0 g. 

 NaOH in a liter). 



(2) Shake well and allow to stand at 

 about 18°C. for 48 hours. 



(3) Remove the nearly transparent milk 

 from the bottom of the funnel and 

 add it to a second separatory funnel. 



(4) Add 250.0 cc. ether and shake well. 



(5) Allow to stand for 48 hours. 



(6) Place the opalescent liquid now in a 

 large sterile flask plug with cotton 

 and heat to 50°C. 



(7) Place under the receiver of a water 

 suction pump for 3 or 4 hours until 

 all the ether is evaporated. 



(8) Add 1.5% pulverized agar. 



(9) Digest for 24 hours at room tem- 

 peratures. 



(10) Heat in steamer for 2-3 hours and 

 filter. 

 Reference: Reinsch (1892 p. 31). 



2160. Abbott's Milk Agar 



Constituents: 



1. Milk 1000.0 cc. 



2. Agar (1.0 to 1.5%) . . . 10.0 to 15.0 g. 

 Preparation: 



(1) Solidify cream-free milk by the addi- 

 tion of 1.0 to 1.5% agar. 

 Sterilization: Not specified. 

 Use: General culture medium. 

 Reference: Abbott (1921 p. 139). 



2161. Raskin's Casein Whey Agar 



Constituents : 



1. Milk 1000.0 cc. 



2. Agar 

 Preparation : 



(1) Allow 1000.0 cc. of skimmed (or 

 whole) milk to stand 48 hours at 

 room temperature. 



(2) Remove any cream that settles out 

 and heat the sour milk at 70 to 80°C. 



