CULTURE MEDIA 27 



precipitate has settled, and filter. Sterilize at a low temperature, 

 about 10 pounds' pressure for 15 minutes, or in the steamer for 

 20 minutes for 3 consecutive days. 



Medium 62 



Ye AST- WATER S ODIUM SULPHITE AgAR 



Agar 15.0 gm. 



Ferric chloride (FeCl3-6H20) or strip of iron. ... 0.1 gm. 



Sodium sulphite (Na2S03) 1.0 gm. 



Yeast water 1 ,000 . cc. 



Reaction pH 7.0. 



For the culture of certain microorganisms it is desirable to add 

 3 per cent of sucrose. 



Medium 63 



ASPARAGIN-SODIUM LACTATE GeLATIN 



Asparagin (C4H8N2O3H2O) 1.0 gm. 



Sodium lactate (NaCsH.^Os) 5.0 gm. 



Dipotassium phosphate (K2HPO4) 0.5 gm. 



Magnesium sulphate (MgS04-7H20) 1.0 gm. 



Iron-ammonium sulphate (FeS04-(NH4)2 



(S04)-6H.O) trace 



Gelatin 120.0 to 150.0 gm. 



Distilled water 1,000 .0 cc. 



Sterilize in the autoclave at 10 pounds' pressure for 15 minutes. 

 Cool in ice water. 



Medium 64 



Beef Extract-sodium Sulphite Agar^ 



Agar 30 . gm. 



Beef extract 3.0 gm. 



Peptone 5.0 gm. 



Glucose 7 10.0 gm. 



Sodium sulphite, 20 per cent solution 10 . cc. 



Distilled water 1,000.0 cc. 



1 Wilson, W. J., and E. Maud McV. Blair, J. Hijg., 24: 111-119, 1925. 



Adjust the reaction to pH 6.6 to 7.0. 



Add the glucose just before sterilization and fill in small flasks 

 of 100 cubic centimeters each. To 100 cubic centimeters of this 

 agar while melted add 1 cubic centimeter of sterile 8 per cent 

 ferric chloride (FeCl3-6H20) solution, 0.6 cubic centimeter of a 



