CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



559 



(5) Add (4), drop by drop, to (1) until the 

 medium is colored blue and then 

 violet blue. 



(6) Distribute into test tubes. 



(7) Add to each test tube a drop of a 

 watery saturated solution of indigo 

 carmine. 



Sterilization: Not specified. 



Use: Differentiation between typhoid 

 bacilli and Bacterium coli. Author re- 

 ported that typhoid bacilli colored the 

 blue medivim a raspberry or carmine red 

 color. Bacterium coli colored the me- 

 dium bluish green and finally decolorized 

 it. 



Reference: Mankowaki (1900 p. 22). 



1787. Rivas' Glucose Agar 

 Same as medium 924, but solidified with 

 agar. 



1788. Hall and EUefson's Gentian Violet 

 Glucose Agar 



Constituents: 



1. Glucose agar 1000.0 cc. 



2. Gentian violet 1 : 100,000 



Preparation : 



(1) Prepare glucose agar in sufficient 

 quantity. 



(2) Add gentian violet so that it be pres- 

 ent in 1: 100,000 dilution. 



Sterilization: Not specified. 



Use : Cultivation of gram positive sporulat- 



ing anaerobes. 

 Variants: Authors used 1:1000 and 1:10,000 



of gentian violet, but best results were 



obtained with 1:100,000 concentration of 



gentian violet. 

 Reference: Hall and Ellef son (1918 p. 336). 



1789. Wilson and Blair's Sulphite Glucose 

 Agar 



Constituents: 



1. Glucose agar (3.0%) 100.0 cc. 



2. Ferric chloride (8.0% soln.) . 1.0 cc. 



3. NaoSOs (20.0%) 10.0 cc. 



Preparation : 



(1) Add 1.0 cc. of an 8.0% ferric chloride 

 solution, 0.6 cc. of a 10.0% sodium 

 hydrate solution and 10.0 cc. of a 

 20.0% anhydrous sodium sulphite 

 solution to freshly boiled melted 

 nutrient glucose agar containing 3.0% 

 agar. 



(2) Add 40.0 cc. of (1) to 40.0 cc. of water. 



(3) Pour into plates. 



(4) When the medium has solidified cover 

 the surface with a layer of (1) mixed 

 with an equal volume of sterile water. 



Sterilization: Not specified. 



Use: To study reduction of sulphite in 

 water analysis. Author reported that a 

 pure water showed no black colonies using 

 40.0 cc. of the water as an inoculum, a 

 potable water showed not more than 4, a 

 sand-filtered water showed not more than 

 one. The author used a similar medium 

 for the enrichment of typhoid bacilli and 

 detection of sulphite reducers in water. 



Variants: The author prepared a similar 

 medium as follows: 



(1) Add 1.0 cc. of an 8.0% ferric chloride 

 solution, 0.6 cc. of a 10.0% sodium 

 hydrate solution and 10.0 cc. of a 

 20.0% anhydrous NajSOs solution to 

 freshly boiled melted nutrient glucose 

 agar containing 3.0% agar. 



(2) Add from 1 to 1000, to 1 to 20,000 

 brilliant green to (1). 



(3) Add 40.0 cc. of (2) to 40.0 cc. of water 

 under investigation. 



(4) Pour into plates. 



(5) When the medium has solidified cover 

 the surface with a layer of (1) mixed 

 with an equal volume of sterile water. 



Reference: Wilson and Blair (1925 p. 112). 



1790. Scheffler's Neutral Red Glucose Agar 



Constituents : 



1. Nutrient agar. . . 1000.0 cc. 



2. Glucose 3.0 or 10.0 g. 



3. Neutral red (con- 

 centrated solu- 

 tion) 10.0, c.O 2.5 cc. 



Preparation: 



(1) Prepare a nut' lent agar. 



(2) Add 0.3 or 1.0% dextrose to (1). 



(3) Add varying amounts of a concen- 

 trated solution of neutral red to 100.0 

 cc. of (2). Amounts used were 1.0, 

 0.5 or 0.25 cc. 



Steri'ization: Not specified. 



Use: Detection of Bact. coli. Author 

 reported that all coli strains investigated 

 gave a fluorescence in a greater or less 

 degree after 48 hours. Fluorescence may 

 usually be obtained after 24 hours using 



