CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



493 



(9) Then add a 36°B. soda solution 

 drop by drop until the red litmus 

 is turned blue. 



(10) Add 10.0 g. agar and dissolve by 

 heating. 



(11) Heat at 115 to 120° in the auto- 

 clave. 



(12) A precipitate forms which com- 

 pletely clears the medium. 



(13) Filter and distribute in tubes. 



(14) Sterilize at a temperature lower 

 than in (11). 



(q) Walbaum (1910). 



(1) Method of preparation of meat 

 infusion not given. 



(2) Add 100.0 g. of finely cut agar to 

 1000.0 cc. of (1). 



(3) Place in the autoclave for 30 min- 

 utes at 0.5 atmosphere extra 

 pressure. 



(4) Prepare a solution of 10.0 g. pep- 

 tone and 5.0 g. NaCl by heating 

 at about 70°C. (Material in 

 which the peptone and NaCl is 

 to be dissolved not specified, 

 whether it be some of the infu- 

 sion or water). 



(5) Place the agar, after autoclaving 

 is completed, on a free flame, and 

 add the distilled water to make 

 up the loss in weight due to 

 evaporation. 



(6) Add (4) to (5). 



(7) Neutralize and boil again for a 

 short time. 



(8) Filter thru a single or double 

 thickness of filter paper. (Re- 

 quires about 10 minutes.) 



(9) Sterilization not specified, 

 (r) Abel (1912). 



(1) Chop 500.0 g. of fat free meat and 

 add to a liter of water at 50°C. 



(2) Keep at 50°C. for 30 minutes and 

 then boil for 30 to 45 minutes. 



(3) Filter or strain the fluid from the 

 heat. 



(4) Make up the fluid to 1 liter. 



(5) Place 20 g. agar in a 3 liter flask 

 and add 500.0 cc. of tap water and 

 2.5 cc. of glacial acetic acid. 



(6) Allow (5) to soak 15 minutes and 

 drain carefully. 



(7) Wash the agar thoroly with 4 lots 

 of water. 



(8) After the last washing allow the 

 agar to drain for 10 minutes. 



(9) Add 500.0 cc. of (4), 10.0 g. pep- 

 tone and 5.0 g. NaCl to the 

 washed agar. 



(10) Autoclave at 115°C. for 30 min- 

 utes or in the steamer for 90 min- 

 utes. 



(11) Make (10) up to a liter by the 

 addition of (4). 



(12) Make slightly alkaline to litmus 

 by the addition of KOH. 



(13) Cool to 60°C. and add the beaten 

 white of an egg. 



(14) Heat in the autoclave for 45 min- 

 utes or in the steamer, for 

 90 minutes. 



(15) Filter thru moistened filter paper, 

 using a hot water funnel. 



(16) Tube. 



(17) Steam for 30 minutes on each of 

 2 successive days. 



(s) Abel (1912). 



(1) Chop 500.0 g. of fat free meat and 

 add to a liter of water at 50°C. 



(2) Keep at 50°C. for 30 minutes and 

 then boil for 30 to 45 minutes. 



(3) Filter or strain the fluid from the 

 meat. 



(4) Make up the fluid to 1 liter. 



(5) Soak 1.5 or 2.0% agar in (4) for 

 several hours. 



(6) Add 1.0% Witte or Chapoteaut's 

 peptone and 0.5% NaCl. 



(7) Heat in the steamer until solution 

 is complete. 



(8) Neutralize to litmus if necessary. 



(9) Heat in the steamer for 15 to 

 30 minutes. 



(10) Filter thru cotton-wool to clarify. 

 The agar may be allowed to 

 solidify in the steamer in straight 

 walled vessels and cut away the 

 bottom opaque layer. 



(11) Sterilize on each of 3 successive 

 days in the steamer or autoclave 

 at 120 °C. for 15 minutes. 



(t) Wilcox (1916) produced toxin by 

 growing B. tetani on the follow- 

 ing medium: 

 (1) Dissolve 5.0 g. agar, 10.0 g. 

 Witte's peptone and 5.0 g. NaCl 

 in 1000.0 cc. veal infusion. 



