CULTURE MEDIA 9 



Medium 4 

 Sodium Caseinate or Nutrose Agar 



Agar 12.5 gm. 



Sodium caseinate (nutrose) 2.0 gm. 



Glucose 1.0 gm. 



Dipotassium phosphate (K2HPO4) 0.2 gm. 



Magnesium sulphate (MgS04-7H20) 0.2 gm. 



Ferrous sulphate (FeS04-7H20) trace 



Tap water 1,000.0 cc. 



Reaction approximately pH 6.8. 



It is not necessary to adjust the reaction of this medium. To 

 secure a clear agar filter through cotton. 



Medium 5 

 Sodium Albuminate AgarI 



Agar 12.5 gm. 



Glucose 1.0 gm. 



Dipotassium phosphate (K2HPO4) 0.5 gm. 



Magnesium sulphate (MgS04-7H20) 0.2 gm. 



Ferric sulphate (Fe2(S04)3'9H20) trace 



Egg albumen (powdered) . 25 gm. 



Water, distilled 1,000.0 cc. 



1 Waksman, S. a., Soil Sci., 14: 283-298, 1922. 



Make a suspension of the egg albumen in a little water (5 

 cubic centimeters), add a drop of phenolphthalein and enough 

 0.1 iV NaOH to dissolve and bring solution to a permanent 

 pink color ; the sodium albuminate is then added to the remainder 

 of the medium. Reaction is about pH 7.2. 



Medium 6 



Nahrstoff-Heyden Agar2 



Agar 12.5 gm. 



Nahrstoff-Heyden 7.5 gm. 



Distilled water 1,000.0 cc. 



2 Hesse, W., and Niedner, Z. Hijg., 29: 454-462, 1898. 



To 500 cubic centimeters of cold distilled water in a flask add 

 7.5 grams of Nahrstoff-Heyden. Shake until a good suspension 

 is obtained and allow the mixture to stand for 30 minutes or more. 



