CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



523 



References: Stroszner (1917-18 p. 223), 

 Zipfel (1917-18, p. 477). 



1713. Besson's Basal Litmus Agar 



Constituents : 



1. Nutrient agar 1000.0 cc 



2. Litmus 

 Preparation: 



(1) Dissolve 2.0 to 4.0% of one of the 

 added nutrients to plain agar. 



(2) Just before use, melt (1) and add a 

 sufficient quantity of litmus to give 

 a light blue color. 



Sterilization: Not specified. 



Use: General culture medium. 



Added nutrients: The author added 2.0 to 



4.0% of any desired carbon source. 

 Variants: Bezan^on gave the following 



method of preparation for a similar 



medium. 



(1) Dissolve 1.0 g. of any desired carbo- 

 hydrate in 20.0 cc. of litmus solution. 



(2) Heat for 20 minutes at 105°C. 



(3) Melt agar and cool to 30 °C. 



(4) Decant (2) and add 1.5 cc. of the lit- 

 mus sugar solution to 5.0 cc. of agar. 



(5) Mix well. 

 References: Besson (1920 p. 59), Bezangon 



(1920 p. 113). 



1714. Mandelbaum's Basal Rosolic Acid 

 Agar 



Constituents : 



1- Agar. . , . , 



2. Rosolic acid (1.0% alcoholic solution). 



Preparation: 



(1) Dissolve an appropriate amount of 

 one of the added nutrients in nutrient 

 agar. 



(2) To each 10.0 cc. of (2) add 0.3 cc. of a 

 1.0% solution of rosolic acid. 



Sterilization: Not specified. 



Use: To differentiate members of colon- 

 typhoid group. The author used a sim- 

 ilar medium to determine both acid pro- 

 duction and hemolysis. 



Added nutrients: The author added an 

 appropriate amount of any desired carbo- 

 hydrate, alcohol, etc. 



Variants: The author added 2.0 cc. of 

 human defibrinated blood to 5.0 cc. of 

 nutrient agar (cooled to 48°C.) containing 

 small amounts of glycerol, lactose or glu- 

 cose. 



Reference: Mandelbaum (1909 p. 2476). 



1715, Zipfel's Regenerated Drigalski's Agar 



Constituents : 



1. Drigalski agar (used). 



2. Peptone. 



3. Meat extract. 



4. Kahlbaum's litmus solution. 

 Preparation : 



(1) Soak used agar slants and plates in 

 a 3.0% HCl solution for one hour. 

 Stir constantly. 



(2) Wash the pieces of agar with water, 

 and soak in water for 24 hours. 



(3) Place in a 1.0%, soda solution until 

 the agar is completely blue. 



(4) Wash with water, and allow the agar 

 to drain. 



(5) Melt the agar and add to 1 liter, 

 8.0 to 10.0 cc. of a 10.0% soda solution, 

 40.0 cc. of a filtered sterile 20.0% 

 peptone solution and 20.0% meat ex- 

 tract or meat equivalent. 



(6) Evaporate 250.0 cc. of Kahlbaum's 

 litmus solution to 50.0 cc. 



(7) Add 20.0 cc. of (6) to one liter of (5). 



(8) The addition of lactose or other ma- 

 terials not specified. 



Sterilization: Method not specified. 



Use: Regenerated medium. This medium 



gave as good results as freshly prepared 



Drigalski agar. 

 Reference: Zipfel (1917-18 p. 478). 



1716. Rothberger's Indicator Agar 



Constituents : 



1. Nutrient agar 



2. Indicator (neutral red, etc.) 

 Preparation : 



(1) Method of preparation of nutrient 

 agar not specified. 



(2) Prepare a saturated solution of neu- 

 tral red. 



(3) To each 10.0 cc. of melted sterile (Ij 

 add 3 or 4 drops of sterile (2). 



Sterilization: Method of sterilization not 



given. 

 Use: Differentiation between typhoid and 



colon bacilli. 

 Variants : 



(a) The author used 3 or 4 drops of a 

 saturated watery solution per 10.0 cc. 

 of agar of one of the following indi- 

 cators instead of neutral red. 



(a) Saffranin. 



(b) Methylene blue. 



