CULTURE MEDIA FOR CULTIVATIOX OF MICROORGANISMS 



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2. Agar (3.0%) 100.0 cc. 



3. Lactose 1-5 g. 



4. Fuchsin acid (0.5%) 10.0 cc. 



5. NaaCOs 

 Preparation : 



(1) Prepare a 3.0% nutrient agar with a 

 reaction slightly alkaline to litmus. 



(2) Dissolve 1.5 g. lactose in 4.0 cc. of 

 distilled boiling water. Boil for 30 

 seconds. 



(3) Prepare a 0.5% solution of acid 

 fuchsin. 



(4) Boil (3) and decolorize by adding four 

 drops of a normal NaaCOs solution. 



(5) Boil again until it assumes a port wine 

 color. 



(6) Add (2) and (5) to 100.0 cc. of (1). 

 Sterilization: Not specified. 



Use: Examination of feces. 



Variants: The author reported that any 

 sugar may replace lactose. The medium 

 may be made more differentiating by the 

 addition of "nutrose or caffeine or mala- 

 chite green (in tested solution as for Lentz 

 and Tietz's medium) or crystal violet 

 (10 drops of a 1 to 1000 solution). In the 

 last two combinations the background is 

 green (or blue) and the coli colonies are 

 violet (or red)." 



Reference: Delta (1915 p. 1053). 



1798. Kindborg's Fuchsin Malachite Green 

 Agar 



Constituents: 



1. Agar 1000.0 cc. 



2. Lactose 14.0 g. 



3. Fuchsin acid (3.0%) 50.0 cc. 



4. Malachite green (1:10,000 



soln.) 10.0 cc. 



Preparation : 



(1) Prepare nutrient agar, neutral to 

 litmus. 



(2) Prepare a 3.0% stock solution of acid 

 fuchsin. 



(3) Prepare a solution of malachite green 

 1:10,000 (from a 0.1: 100). 



(4) Dissolve 14.0 g. lactose in about 40.0 

 cc. water. 



(5) When the agar has cleared somewhat 

 by settling, add 50.0 cc. of the red and 

 10.0 cc. of the green liquid and finally 

 the lactose solution. 



(6) Pour sterile (5) into sterile plates. 

 Sterilization : Sterilize (5) one-half hour in 



the autoclave. 



Use: Detection of typhoid fever and dys- 

 entery. Author reported that typhoid, 

 paratyphoid and dysentery bacilli gave 

 light colorless colonies. Coli forms gave 

 small red colonies. They were inhibited. 

 Cholera colonies were colorless but the 

 medium was not selective for this 

 organism. 



Reference: Kindborg (1915-16 p. 445). 



1799. Bitters' China Blue Malachite-green 



Agar (Klinimer) 



Constituents : 



1. Agar (2.0 or 3.0%) 1000.0 cc. 



2. Lactose (2.0%) 20.0 g. 



3. China blue (Hochst. sat. 

 solution) 



4. Malachite green (Hochst. 



0.1% soln.) 25.0 cc. 



Preparation : 



(1) Prepare a 2.0 or 3.0% nutrient agar. 



(2) Neutralize to litmus by the addition 

 of NaOH. 



(3) Add 2.0% lactose. 



(4) Boil several minutes. 



(5) Add 9 drops of a saturated solution 

 of China blue (Hochst.) to each 100.0 

 cc. of agar. 



(6) Add 2.5 cc. of a 0.1% solution of 

 Hochst. crystalline extra malachite 

 green to each 100.0 cc. (The mala- 

 chite green may be omitted.) 



(7) Heat for 10 minutes in a steamer. 



(8) Pour in plates. 

 Sterilization: Not specified. 



Use: Differentiation of colon typhoid 

 group. Author reported that coli colo- 

 nies were blue; typhoid colonies yellow 

 or colorless. 



Reference: Klimmer (1923 p. 217). 



1800. Liebermann and Acels' Congo Red 



Agar (Klimmer) 



Constituents: 



1. Nutrient agar 1000.0 cc. 



2. Lactose 15.0 g. 



3. Congo red 3.0 g. 



Preparation : 



(1) Add 15.0 g. of lactose and 3.0 g. of 

 Congo red to a liter of slightly alka- 

 line nutrient agar. 



(2) Boil. 



(3) Mix thoroly. 

 Sterilization: Not specified. 



