740 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



dium gave as good results as the average 

 grade of serum media. 

 Reference: Huntoon (1918 p. 171). 



2293. Rosenberg's Basal Extract Gelatin 



Constituents : 



1. Water 1000.0 cc. 



2. Gelatin (10.0%) 100.0 g. 



3. Peptone (Koch) (4.0%) 40.0 g. 



4. Meat e.xtract (0.5%) 5.0 g. 



Preparation : 



(1) Dissolve 2, 3 and 4inl. 



(2) Dissolve one of the added nutrients 

 in (1). 



(3) Gelatin may be neutralized by the 

 addition of Na^COs or used without 

 adjusting the reaction. 



Sterilization: Not specified. 



Use: Bacterial count of water. Used also 



as a general culture medium. 

 Added nutrients: Rosenberg added 0.5% 



of any desired sugar. 

 Variants : 



(a) Same as medium 1693, but using 

 20.0 g. gelatin instead of 10.0 g. of 

 agar. The agar was used for those 

 organisms liquefying gelatin. 



(b) Percival prepared a medium as fol- 

 lows: 



(1) Dissolve 5.0 g. Lemco meat ex- 

 tract and 10.0 g. Witte's peptone 

 in 1000.0 cc. water at ordinary 

 room temperature. 



(2) Add 100.0 g. gelatin (best sheet) 

 and soak for 30 minutes. 



(3) Heat in a water bath until the 

 gelatin is dissolved. Shake from 

 time to time. 



(4) Neutralize to phenolphthalein by 

 the addition of normal caustic soda. 



(5) Add 10.0 cc. of normal HCl to each 

 1000.0 cc. of the medium. 



(6) Cool the medium to 40°C. and 

 slowly add the white of an egg 

 well beaten up in a little water. 



(7) Heat in the steam sterilizer or 

 water bath. 



(8) Filter the hot solution thru 

 moistened hot filter paper into a 

 sterilized flask. Use a hot water 

 funnel for filtering. 



(9) Tube in 8 to 10.0 cc. quantities. 

 (10) Steam for 20 minutes on 3 suc- 

 cessive days. 



(11) Add 20.0 g. lactose or glucose. 



(12) To prepare litmus glucose gelatin 

 add 2.0% glucose and enough 

 Kubel-Tiemann neutral litmus to 

 color it a purple tint before steri- 

 lization. 



References: Rosenberg (1886 p. 452), Ban- 

 ning (1902 p. 426), Percival (1920 p. 47). 



2294. Burger's Basal Fuchsin Sulphite 

 Extract Gelatin 



Constituents : 



1. Distilled water 900.0 cc. 



2. Meat extract (Liebig's) 10.0 g. 



3. Peptone (Witte Rostock) .... 10.0 g. 



4. NaCl 5.0 g. 



5. Gelatin 100.0 g. 



6. NaaSOa 2.5 g. 



7. Fuchsin, ale. solution 5.0 cc. 



8. Soda (crystalline) 1.0 g. 



Preparation: 



(1) Dissolve 2, 3 and 4 in 1 by heating in 

 the steamer. 



(2) Allow (1) to cool. 



(3) Add 100.0 g. of gelatin to the non- 

 filtered nutrient medium. 



(4) Allow to soak for an hour or to stand 

 in the ice box over night. 



(5) Dissolve the gelatin in the steamer 

 requiring about 30 minutes. 



(6) Neutralize with N/1 NaOH to lit- 

 mus. Shake well after addition of 

 NaOH. 



(7) Make alkaline by the addition of 

 1.0 g. crystalline soda. 



(8) Add 10.0 g. of one of the added nu- 

 trients either in a solid state or in a 

 concentrated solution. 



(9) Cool to about 40-50°C. 



(10) Dissolve 1.5 g. of egg albumin in 

 25.0 cc. of luke warm water, and 

 add to (9). Shake thoroly. 



(11) Boil in the steamer for about 

 30 minutes. 



(12) Filter hot, thru sterile paper at a 

 temperature of 50 or 60°C. This 

 may be carried out in the steamer 

 after the flame has been removed. 

 May allow to filter over night. 



(13) Distribute in 100.0 cc. lots. 



(14) When ready for use, melt sterile (13) 

 and to each 100.0 cc. add 5.0 cc. of a 

 saturated filtered alcoholic solution 

 of fuchsin and 02.5 g. of crystalline 



