CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



379 



Colon bacilli gave a pea yellow after 24 

 hours. If a few more drops of picric acid 

 be added to the medium typhoid will not 

 grow while B. coli will cause a slight 

 change in color. This indicator may be 

 added to media other than milk. 

 Reference: Calandra (1910 p. 570). 



1298. Park and Krumwiede's Litmus 

 Glycerol Milk Solution 



Constituents: 



1. Milk 1000.0 cc. 



2. Glycerol 50.0 cc. 



3. Litmus, 5.0% watery solu- 

 tion Merck's 50.0 cc. 



Preparation 



(1) Free milk from cream. 



(2) Add 5.0% glycerol and 5.0% of a 5.0% 

 watery solution of Merck's purified 

 litmus. 



Sterilization: Method not given. 



Use: Cultivation of tubercle bacilli. After 



inoculation seal either with cork alone or 



preferably dip the cotton stopper also in 



paraffin. 

 Reference: Park and Krumwiede (1910 p. 



215). 

 1299. Smith's Litmus Milk Solution 



Constituents: 



1. Milk. 



2. Litmus. 

 Preparation: 



(1) Obtain fresh milk and free from fat 

 by running the milk thru a separator 

 or by allowing the cream to rise 

 spontaneously. 



(2) Test the reaction. It should not be 

 more than +2. 



(3) Tube. 



(4) Add sufficient sterile litmus solution 

 to give a distinct pale blue tinge to 

 the milk, to sterile (3). 



Sterilization: Sterilize at 100°C. using the 

 fractional method. 



Use: General culture medium. 



Variants: Various investigators have pre- 

 pared media in a number of similar ways. 

 Some investigators used azolitmin instead 

 of litmus, and some sterilized the medium 

 in the autoclave. Others sterilized the 

 medium after the litmus was added. 

 The differences in preparation did not 

 seem to be of sufficient importance to 



warrant a separate discussion for each 

 investigator. 

 References: Smith (1902 p. 106), Frost 

 (1903 p. 66), Heinemann (1905 p. 28), 

 Smith (1905 p. 48), Committee A.F.H.A. 

 (1905 p. 109), Roddy (1917 p. 41), Ball 

 (1919 p. 83), Tanner (1919 p. 71), Percival 

 (1920 p. 57), Besson (1920 p. 59), Bezan- 

 gon (1920 p. 116), Abbott (1921 p. 139), 

 Levine (1921 p. 109), Dopter and Sacque- 

 pee (1921 p. 122), Giltner (1921 p. 25), 

 Harvey (1921-22 p. 94), Pitfield (1922 p. 

 117), Stitt (1923 p. 39), Park, Williams and 

 Krumwiede (1924 p. 120). 



1300. Sherman and Albus' Indicator Milk 

 Solution 



Constituents: 



1. Distilled water 1000.0 cc. 



2. Milk 1000.0 cc. 



3. Methylene blue (medicinal) . 0.5 g. 

 Preparation: 



(1) Dissolve 0.5 g. medicinal methylene 

 blue in 1000.0 cc. distilled water. 



(2) Add 1.0 cc. of sterile (1) to each 10.0 

 cc. of sterile milk. 



Sterilization: Sterilize the dye and milk 

 separately. Method not given. 



Use: To demonstrate the reduction by 

 streptococci of the Streptococcus lacticus 

 and Streptococcus pyogenes types. The 

 medium was decolorized if reduction 

 occurred. 



Variants: The author used the following 

 variants: 



(a) Dissolved 1.0 g. of Kahlbaum's indigo 

 carmine in 1000.0 cc. distilled water 

 and used instead of methylene blue 

 solution. 



(b) Dissolved 1.0 g. of GriJbler's neutral 

 red in 1000.0 cc. of distilled water and 

 used instead of the methylene blue 

 solution. 



Reference: Sherman and Albus (1918 p. 

 167). 



1301. Harvey's Brom Cresol Purple Milk 

 Solution 



Constituents: 



I ^^li\\^ 1000.0 cc. 



2. Brom cresol purple 

 Preparation: 



(1) Dissolve brom cresol purple in a 

 minimum amount of alcohol, and 



