578 



CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



water by steaming in Arnold, or 

 boiling over flame. 

 (9) Filter until clear and make up to 

 250.0 cc. with distilled water. 



(10) Mix (7) and (9). 



(11) Place 30.0 g. agar in 2000.0 cc. dis- 

 tilled water and let stand 24 hours. 



(12) Pour ofE water and add 2000.0 cc. 

 more water. 



(13) Allow to stand 24 hours, pour on 

 cotton flannel cloth in funnel and 

 wash once more with one liter dis- 

 tilled water. Press out as much 

 water as possible. 



(14) Add enough water to have weight of 

 1030.0 cc. of agar and water. 



(15) Dissolve in Arnold and filter thru 

 cotton flannel until clear. 



(16) Add 500.0 cc. of (15) to (10). 

 Sterilization: Method not given. 



Use: To determine number of bacteria in 

 milk. Authors reported that the medium 

 gave high count. Colonies were large 

 and easy to count. 



Variants: The authors specified that indi- 

 cators and glucose or lactose might be 

 added if desired. 



Reference: Ayres and Mudge (1920 p. 568). 



1849. Conradi-Drigalski's Crystal Violet 



Litmus Agar (Park, Williams 



and Krumwiede) 



Constituents: 



1. Water 1000.0 cc. 



2. Agar 20.0 g. 



3. NaCl 5.0 g. 



4. Peptone 20.0 g. 



5. Nutrose 10.0 g. 



6. Beef extract (Liebig's) 4.0 g. 



7. NaOH (N/1) 50.0 cc. 



8. Litmus (Kubel and Thie- 

 mann's) 130.0 cc. 



9. Crystal violet (1 : 1000) .... 10.0 cc. 

 10. Lactose 15.0 g. 



Preparation : 



(1) Dissolve 2, 3, 4, 5, 6 and 7 in 1 in an 

 autoclave. 



(2) Cool and clarify with eggs. 



(3) Adjust the reaction moderately but 

 distinctly alkaline to litmus. 



(4) To each liter of (3) add 130.0 cc. of 

 Kubel and Thiemann's litmus solu- 

 tion, 10.0 cc. of a 1 to 1000 solution 

 of crystal violet, and 15.0 g. of lactose. 



(5) Heat in an Arnold sterilizer 10 

 minutes to obtain thoro mixing. 



(6) Distribute in tubes or bottles. 

 Sterilization: Sterilize in the Arnold 



sterilizer. 



Use: Differentiation of colon-typhoid 

 group. Author reported that acid pro- 

 duction indicated by black colonies, or 

 colonies having black centers. Omit the 

 saccharose when used for dysentery 

 isolation. B. dysenteriae (Shiga) may 

 fail to grow on this medium. Omit the 

 crystal violet if to be used for dysentery. 



Reference: Park, Williams and Krumwiede 

 (1924 p. 128). 



1850. Tausz and Peter's Ragit Nutrose Agar 



Constituents : 



1. Water 1000.0 cc. 



2. Ragit nutrose agar 52.0 g. 



3. Congo red tablets (Merck) . 18.0 g. 

 Preparation : 



(1) Boil 52.0 g. ragit nutrose agar in one 

 liter of water for one hour in the 

 steamer. Shake occasionally. 



(2) Filter. 



(3) Distribute in 100.0 cc. lots. 



(4) To each 100.0 cc. of (3) add 1.8 g. of 

 Congo red tablets (Merck). The 

 tablets contain lactose and congo red. 



(5) Boil for 15 or 20 minutes. 



(6) Pour into Petri dishes. 

 Sterilization: Not specified. 



Use: Cultivation of Bacterium aliphaii- 

 cum, Bacterium aliphaticum liquefaciens, 

 paraffin bacteria. Authors reported that 

 ragit nutrose agar is a commercial 

 powder. Congo red tablets contain lac- 

 tose and Congo red. 



Reference: Tausz and Peter (1919 

 p. 508). 



1851. Hunter's Trypsinized Casein Extract 



Agar 



Constituents : 



1. Water 1000.0 cc. 



2. Casein 15.0 g. 



3. Peptone 15.0 g. 



4. Beef extract 3.0 g. 



5. Agar 15.0 g. 



6. Lactose 15.0 g. 



7. Sodium oleate (2.0% soln.) . . 50.0 cc. 



