706 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



medium containing 0.4 g. Lemco 

 meat extract, 0.4 g. NaCl and 25.0 g. 

 agar per liter. The reaction of the 

 medium was 1.0% alkaline to phen- 

 olphthalein. 

 References: Hiss (1902 p. 158), Musgrave 



and Clegg (1905 p. 335), Walker (1908 p. 



490), Linde (1913 p. 373), Zikes (1915 p. 



543), Besson (1920 p. 43), Harvey (1921-22 



p. 94). 



2186. Bacto Starch Agar (Dehydrated) 



Constituents : 



1. Distilled water 



2. Beef extract, Bacto 3.0 g. 



3. Agar, Bacto 12.0 g. 



4. Starch, Soluble, Difco 10.0 g. 



Preparation : 



(1) Dissolve 25.0 g. of Bacto starch agar 

 (dehydrated) in 1000.0 cc. of distilled 

 water by boiling or autoclaving, 

 preferably the latter. 



(2) Restore loss if necessary. 



(3) Distribute as desired. 

 Sterilization: Sterilize for 20 minutes at 15 



pounds pressure. 

 Use: Culture medium. 

 Reference: Digestive Ferments Co. (1925 



p. 14). 



2187. Hiss' Glucose Extract Agar 



Constituents: 



1. Distilled water 1000.0 cc. 



2. Agar 15.0 g. 



3. Extract Liebig's 5.0 g. 



4. NaCl 5.0 g. 



5. Glucose 10.0 g. 



Preparation : 



(1) Dissolve the agar in water by boiling 

 over a free flame for 30 to 45 minutes. 



(2) Dissolve Liebig's extract and salt in 

 (1). 



(3) Filter thru paper. 



(4) Dissolve the glucose in (3). 



(5) The reaction is usually 0.8% acid to 

 phenolphthalein. 



(6) Tube in 10.0 cc. lots. 

 Sterilization: Sterilize in the usual manner 



at 100°C. on 3 successive days. 

 Use: Differentiation between typhoid, 

 colon and other allied bacilli. The 

 author reported that the typhoid bacilli 

 gave threaded irregular colonies. Colon 

 colonies were large and smooth. If 



medium be clarified with egg whites a 

 more alkaline medium was obtained which 

 allowed better differentiation. One cc. 

 NaOH added to the medium also allowed 

 better differentiation. 

 Variants : 



(a) The medium may be clarified with egg 

 white. 



(b) One cubic centimeter of normal 

 NaOH may be added. 



(c) The medium may be prepared as 

 follows: 



(1) Dissolve 15.0 g. agar in water by 

 boiling for 30 to 45 minutes over a 

 free flame. 



(2) Dissolve 5.0 g. Liebig's extract in 

 (1). 



(3) Coagulate the whites of two eggs in 

 (2) to clarify. 



(4) Filter thru absorbent cotton. 



(5) Dissolve 10.0 g. glucose in (4). 



(6) Reaction is 0.75% acid to phenol- 

 phthalein. 



(7) Tube in 10.0 cc. lots. 



(8) Sterilize in the Arnold in the usual 

 manner on three successive days. 



Reference: Hiss (1902 pp. 156, 158). 



2188. Tanner's Malachite Green Extract 

 Agar 



Constituents : 



1. Water 1000.0 cc. 



2. Meat extract, Liebig. 3.0 g. 



3. Agar 30.0 g. 



4. Sucrose 10.0 g. 



5. Malachite green 



(2.0% solution) 2.0 to 2.9 cc. 



Preparation : 



(1) Dissolve 2 in 1. 



(2) Acidify with 7.5 cc. normal HCl. 



(3) Dissolve 30.0 g. agar in (2) by 

 boiling. 



(4) Neutralize by adding 7.0 cc. normal 

 NaOH until neutral to litmus. 



(5) Add 5.0 cc. of normal NajCOa. 



(6) Heat in an Arnold for several hours. 



(7) Add 100.0 cc. of 10.0% sucrose 

 solution to (6). 



(8) Store in 100.0 cc. quantities. 



(9) Before use redissolve and add 2.0 to 

 2.9 cc. of a 2.0% malachite green 

 (trade mark Hochst. 120) to each 

 100.0 cc. of medium. Prepare the 



