CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



491 



(2) Add 10.0 g. of finely cut agar to 



1000.0 cc. of (1). 

 <3) Allow to stand until the agar is 



completely soaked up. The time 



required depends on the type of 



agar used. 



(4) Boil for about 45 minutes with 

 constant stirring. 



(5) Prepare a solution of 5.0 g. NaCl 

 and 10.0 g. peptone by heating 

 at about 70°C. (material in which 

 the peptone and NaCl is to be 

 dissolved not specified, whether 

 it be water or of some of the 

 infusion). 



(6) Add distilled water to (4) to make 

 up the loss due to evaporation. 



(7) Add (5) to (6). 



(8) Neutralize and boil again for a 

 short time. 



(9) Filter thru a single folded filter 

 paper, placing the funnel and agar 

 in an autoclave (requires 20-40 

 minutes depending on the kind of 

 agar). 



(10) Sterilization not specified, 

 (k) Migula (1901). 



(1) Mix 500.0 g. of finely chopped 

 lean beef with one liter of water, 

 and allow to stand in the ice box 

 for 12 to 24 hours. 



(2) Press the liquid thru a towel and 

 make up the volume to one liter. 



(3) Boil in the steam cooker for 

 30 minutes. 



(4) The infusion may be boiled for a 

 hour before removing the meat 

 and then filtered thru paper. 

 If the liquid is still red, boil 

 again for 15 minutes. 



(5) Filter when cold to remove fat. 



(6) Dissolve 15 g. agar, 0.5% NaCl 

 and 1.0% Witte's peptone in (5) 

 by boiling in a paraffin oven or an 

 autoclave. 



(7) Neutralize carefully by the addi- 

 tion of concentrated Na2C03 solu- 

 tion until litmus paper is colored 

 violet. 



(8) Add soda solution as desired. 

 Generally 10.0 cc. of a 15.0% soda 

 solution is added per liter. 



(9) Place the agar in a tall narrow 

 flask and boil in the steamer for 

 one hour. 



(10) Cool to 90°C. and allow to remain 

 at that temperature for several 

 hours. 



(11) Decant the clear agar and filter 

 thru a folded filter paper. Filter 

 at 90°C. The sediment may be 

 filtered thru another filter paper. 



(12) 1.0 to 2.0% glucose may be added. 



(13) Distribute in tubes or flasks. 



(14) Boil for one hour to sterilize. 

 (1) Thoinot and Masselin (1902). 



(1) Macerate 500.0 g. of lean beef 

 with 1 liter of water for several 

 hours. 



(2) Pass thru a linen cloth and ex- 

 press the juice from the meat. 



(3) Add 10.0 g. peptone and 5.0 g. 

 NaCl. 



(4) Boil and filter. 



(5) Make slightly alkaline by the 

 addition of soda. 



(6) Add 15.0 g. of finely chopped agar 

 and heat until dissolved. Stir 

 constantly. 



(7) Pass thru a sieve. 



(8) Cool to 55 °C. and add the white 

 of an egg beaten up in 500.0 cc. 

 of water. Mix well. 



(9) Heat to 120°C. for 45 minutes. 



(10) Filter thru paper (hot filtration). 



(11) Distribute in tubes. 



(12) Heat at 115°C. for 20 minutes, 

 (m) Frost (1903). 



(1) Add 15.0 g. of agar to 500.0 cc. of 

 water and dissolve by heating to 

 120°C. in the autoclave, closing 

 off the gas and allowing to cool 

 or boil until the agar is dissolved 

 (about 30 minutes) and make up 

 the loss of water due to evap- 

 oration. 



(2) Free 500.0 g. of lean beef from 

 fat and connective tissue and 

 mince. 



(3) Add 500.0 g. of water to (2) and 

 set in the ice chest for 12 to 

 24 hours. 



(4) Squeeze thru a cloth and add dis- 

 tilled water to the filtrate to make 

 500.0 cc. 



(5) Add 10.0 g. of peptone and 5.0 g. 

 NaCl. 



(6) Heat until solution is complete. 



(7) Neutralize to phenolphthalein. 



(8) Cool to 60°C. 



