CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



451 



Preparation : 



(1) Dissolve 37.5 g. of Levine's Eosine 

 Methylene Blue Agar (Dehydrated) 

 in 1000.0 cc. of water by boiling, or 

 better autoclaving. 



(2) If sterilized at 15 pounds for 20 

 minutes pH = 7.1±. 



Sterilization : Sterilize in the usual manner. 

 Use: Differentiation of the coli-aerogenes 



group. 

 Reference: Digestive Ferments Co. (1925 



p. 10). 



1557. Bacto Endo Agar (Dehydrated) 

 Formula of Levine 



Constituents: 



1. Distilled water 



2. K2HPO4 3.5 g. 



3. Peptone, Bacto 10.0 g. 



4. Agar, Bacto 15.0 g. 



5. Lactose, Bacto 10.0 g. 



6. NasSOa 2.5 g. 



7. Fuchsin, Basic, (10.0% ale. 



soln.) 5.0 cc. 



Preparation: 



(1) Dissolve 41.5 g. of Bacto Endo Agar 

 (Dehydrated) in 1000.0 cc. of distilled 

 water by using as little heat as 

 possible, autoclaving is recom- 

 mended. 



(2) If sterilized at 15 pounds for 20 

 minutes pH = 7.5 ±. 



Sterilization: Sterilize in the usual manner. 

 Use: Differentiation of colon-typhoid 



group. 

 Reference: Digestive Ferments Co. (1925 



p. 11). 



1558. Levine's Eosine Methylene Blue Agar 



Constituents: 



1. Distilled water.., 1000.0 cc. 



2. Peptone (Difco) 10.0 g. 



3. K2HPO4 2.0 g. 



4. Agar 15.0 g. 



5. Lactose 10.0 g. or sterile 



20.0% solution) 50.0 cc. 



6. Eosine (yellowish 2.0% aq. 

 solution) 20.0 cc. 



7. Methylene blue (5% aq. 



solution) 20.0 cc. 



Preparation : 



(1) Dissolve 2, 3 and 4 in 1 by boiling. 



(2) Make up loss due to evaporation. 



(3) Place measured quantities in flasks. 



(4) Just prior to use add to each 100.0 

 cc. of sterile (3) 1.0 g. of sterile lactose 

 or 5.0 cc. of 20.0% sterile lactose 

 solution. Also to each 100.0 cc. add 

 2.0 cc. of a 2.0% aqueous solution of 

 eosin (yellowish) and 2.0 cc. of a 0.5% 

 aqueous methylene blue solution. 



(5) Mix thoroly and pour into sterile 

 petri dishes. Allow to harden in the 

 incubator. 



Sterilization: Sterilize (3) at 15 pounds 

 pressure for 15 minutes. 



Use: To differentiate between B. coli and 

 B. aerogenes. Author reported that 

 Bad. coll colonies well isolated 3-4 mm. 

 in diameter. Colonies flat, sometimes 

 concave, dark and sometimes with a 

 green metallic sheen. Bad. aerogenes 

 isolated colonies 4r-6 mm. in diameter; 

 neighboring colonies run together 

 quickly, colonies raised and convex; 

 centers deep brown. By reflected light 

 colonies are much lighter than Bad. coli. 



Variants: Skinner and Murray added 

 1 : 100,000 crystal violet to the medium to 

 inhibit the development of spreaders. 



References: Levine (1918 p. 43), Tanner 

 (1919 p. 54), Levine (1921 p. 117), Harvey 

 (1921-22 p. 92), A. P. H. A. (1923 p. 96), 

 (1925 p. 99), Skinner and Murray (1924 p. 

 590). 



1559. Levine's Endo Agar 

 Constituents : 



1. Distilled water 1000.0 cc. 



2. Peptone (Difco)....,. . 10.0 g. 



3. Dipotassium phos- 

 phate (K2HPO4) 2.0 to 5.0 g 



4. Agar 15.0 to 30.0 g. 



5. Lactose 10.0 g. 



6. Fuchsin (10.0% soln.) 



7. Na.SOa (10.0% soln.) 



Preparation : 



(1) Boil 2, 3 and 4 in 1 until solution is 

 complete. 



(2) Make up any loss due to evaporation. 



(3) Not necessary to filter or adjust the 

 reaction. 



(4) Distribute in measured quantities 

 and sterilize. 



(5) When ready for use add 1.0 g. of 

 sterile lactose, or 5.0 cc. of a 20.0% 

 sterile lactose solution, 0.5 cc. of a 

 10.0% (saturated) alcoholic solution of 



