CULTURE MEDIA FOR CULTIVATION OF MICROORGANISMS 



497 



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

 NaCl to (5). 



(7) Neutralize. 



(8) Boil. 



(9) Readjust the reaction if neces- 

 sary. Alkaline agar may be pre- 

 pared by adding 7.0 cc. of normal 

 soda solution to a liter of agar 

 neutral to litmus. 



(10) Filter. 



(12) Distribute as desired. 



(13) Sterilize by steaming for 40 

 minutes, on one day, or for 

 15 minutes on each of 3 succes- 

 sive days. 



(ee) Park, Williams and Krumwiede 

 (1924). 



(1) Dissolve 10.0 g. peptone and 5.0 g. 

 NaCl in 1000.0 cc. infusion broth 

 (see variant (11) medium 779) by 

 heating to 50°C. 



(2) Add 15.0 g. agar to (1) and dis- 

 solve by heating in the autoclave 

 at 10 to 15 pounds pressure for 

 30 minutes, or by boiling over the 

 free flame. 



(3) If boiled over a free flame, make 

 up the loss in weight by the addi- 

 tion of water. 



(4) Adjust the reaction. 



(5) Cool to 50°C. and add one egg. 



(6) Heat in the autoclave at 10 to 

 15 pounds for 30 minutes or Ar- 

 nold sterilizer for 1 hour. P ilter. 



(7) Test the reaction and adjust if 

 necessary. 



(8) If more than 0.2% normal soda 

 is required per liter, heat again 

 for 10 minutes. 



(9) Filter thru cotton. 



(10) Distribute in tubes or flasks. 



(11) Sterilize at 15 pounds pressure 

 for 30 minutes. 



(ff) Park, Williams and Krumwiede 

 (1924). 

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

 NaCl and 15.0 g. agar in infusion 

 broth. (See variant (11) me- 

 dium 779) by heating in the auto- 

 clave at 10 to 15 pounds pressure 

 for 30 minutes or by boiling over 

 the free flame. 



Remainder of preparation the 

 same as variant (ee) above. 



(gg) Park, Williams and Krumwiede 

 (1924). 



(1) Prepare double strength infusion 

 broth, using double the amount of 

 beef or veal. (See infusion broth 

 medium 779, variant (kk) or (11) 

 for the method.) 



(2) Add double the amount of pep- 

 tone, (20.0 g. per liter) and NaCl 

 (10.0 g. per liter) to (1). 



(3) Adjust the reaction. 



(4) To an equal quantity of water 

 (1000.0 cc.) add a double quantity 

 (30.0 g.) of agar and dissolve. 



(5) Cool the agar below 50°C. 



(6) Mix equal parts of (3) (double 

 strength infusion broth) and (5) 

 (3.0% agar). 



(7) Test the reaction and adjust if 

 necessary. 



Remainder of preparation as 

 from step (5) variant (ee) above. 

 References: Jacobi (1888 p. 536), Schultz 

 (1891 pp. 57, 60), Frothingham (1895 

 p. 55), Ravenel (1898-1900 p. 89), Jensen 

 (1898 p. 406), Committee A. P. H. A. (1899 

 p. 77), Ravenel (1899 p. 606), Thalmann 

 (1900 p. 829), Walbaum (1901 p. 796), 

 Migula (1901 p. 17), Thoinot and Mas- 

 selin (1902 p. 33), Frost (1903 p. 16), 

 Smith (1905 p. 195), Guillemard (1906 

 p. 157), Walbaum (1910 p. 796), Abel (1912 

 pp. 17, 18), Wilcox (1916 p. 333), Meier 

 (1918 p. 435), Harvey (1921-22 pp. 66, 70, 

 71), Abbott (1921 p. 129), Dopter and 

 Sacquepee (1921 p. 125), Pitfield (1922 

 p. 117), Klimmer (1923 p. 193), Park, 

 Williams and Krumwiede (1924 p. 117). 



1662. Zettnow's Meat Infusion Agar 



Constituents : 



1. Water 5000.0 cc. 



2. Meat (horse) 3000.0 g. 



3. Agar 11-5 g. 



4. (NH4)2S04 1.0 g. 



5. Peptone 1.0 g. 



6. KNO3 1.0 g. 



Preparation : 



(1) Heat 3000.0 g. of horse (or other 

 cheap fat-free meat) meat with 

 5000.0 cc. of tap water, or distilled 

 water, to 60-65°C. for 1 to 11 hours, 

 stirring occasionally. 



