CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



235 



(5) Boil for 30 minutes. 



(6) Press the liquid from the meat 

 in a meat press. 



(7) Mix the meat with more water, 

 and press out again. 



(8) Bring the volume of the com- 

 bined liquids to 1 liter. 



(9) Dissolve 20.0 g. peptone and 5.0 g. 

 NaCl in (8). 



(10) Adjust the reaction to 1.2% acid 

 with phenolphthalein as an indi- 

 cator. 



(11) Filter until perfectly clear. 



(12) Sterilize in the autoclave. 

 (ff) Pitfield (1922). 



(1) Cover 500.0 g. of finely cut fat 

 free beef with 1000.0 cc. of water. 



(2) Shake well and place on ice over 

 night. 



(3) Squeeze out the fluid by means of 

 a cloth and make up the volume 

 to 1 liter. 



(4) Inoculate with a culture of the 

 colon bacillus. 



(5) Allow to stand at room tempera- 

 ture over night. 



(6) Boil and add 10.0 g. Witte's pep- 

 tone and 5.0 g. NaCl. 



(7) Weigh the sauce pan and contents 

 and heat to 60°C. 



(8) Make up the loss in weight by the 

 addition of water. 



(9) Neutralize to litmus. 



(10) Boil 5 minutes. 



(11) Make up the loss in weight by the 

 addition of water. 



(12) Adjust the reaction as desired 

 (+0.5 to +1.5%). 



(13) Filter. 



(14) Distribute into flasks or tubes. 



(15) Sterilize (method not given). 

 (gg) Hartley (1922) used the following 



medium for diphtheria toxin pro- 

 duction: 



(1) Soak 1 pound of lean finely 

 chopped horse meat in 1000.0 cc. 

 of tap water over night. 



(2) Raise the temperature to 95°C. 

 the following morning. 



(3) Allow to cool slightly and filter 

 thru paper pulp. 



(4) Adjust the reaction of the filtrate 

 to pH = 8.0. 



(5) Dissolve 2.0% Park Davis bac- 

 teriological peptone and 0.5% 

 NaCl in (4). 



(6) Adjust to pH = 8.0. 



(7) Distribute in desired containers. 



(8) Pass steam thru the autoclave 

 for one hour after which slowly 

 raise the pressure to 10 pounds 

 (time about 30 minutes) and keep 

 at this temperature for 30 

 minutes. 



(hh) Stitt (1923). 



(1) Cut up 500.0 g. fat-free meat in 

 a sausage mill. 



(2) Pour 1000.0 cc. of water over (1). 



(3) Keep in the ice chest over night. 



(4) The following morning skim off 

 the scum of fat by means of a 

 piece of absorbent cotton. 



(5) Squeeze out the infusion thru a 

 strong muslin cloth, making the 

 amount up to 1000.0 cc. 



(6) Dissolve 1.0% Witte's peptone 

 and 0.5% NaCl in (5). Mix the 

 salt and peptone with a little of 

 the infusion and prepare a paste 

 of the mixture in a mortar before 

 adding it to (5). 



(7) Add sufficient normal NaOH to 

 make the reaction +1.0 to phenol- 

 phthalein. 



(8) Place in the inner chamber of a 

 rice cooker and bring to boil. 

 Boil for 20 minutes. It is neces- 

 sary to have NaCl or CaClj in 

 the outer chamber. Do not stir 

 the medium. 



(9) Filter thru a wet filter paper. 



(10) Make up the volume to 1000.0 cc. 

 by the addition of distilled water. 



(11) Readjust or record the reaction. 



(12) Filter if the reaction is adjusted 

 in (11). 



(13) Sterilize in the autoclave at 

 115°C. for 15 minutes or in the 

 Arnold on 3 successive days. 



(ii) Stitt (1923). 



Prepare the medium like the above 

 variant (gg) (1) thru (12). 



(13) Inoculate with 5.0 cc. of a 24-hour 

 culture of the colon bacillus. 



(14) Incubate over night at 37°C. 



(15) Boil in a sauce pan. 



