136 CULTURE MEDIA AND THEIR STERILIZATION 



Cohn's Solution. 



Phosphate of potash 0.10 gram 



Crystals of sulphate of magnesium . 0.10 gram 



Tribasic phosphate of calcium . ' . ; .. , . . . . . 0.01 gram 

 Ammonium tartrate . . . . . ' . .'....'. . 0.20 gram 



Aq. dest. . . .... . . v . . . . , . 20.00 c.c. 



Ushinsky's Solution. 



Chloride of sodium . . . . . . . .... 5 to 7 grams 



Chloride of calcium . . '. ... . ^ . . . 0.1 gram 



Sulphate of magnesium . . ... .... 0.2 to 0.4 gram 



Dipotassium phosphate . . . . . .... . 2 to 2.5 grams 



Ammonium lactate (acid) 6.7 gram 



Asparaginate of sodium . . . . . . . . . 3.5 gram 



Dissolve in 1000 c.c. of distilled water and add 30 to 40 c.c. of 

 glycerin. Sterilize by the discontinuous method. 

 Fraenkel's Solution. 



Chloride of sodium . . .'...*. . . . 5 grams 



Potassium diphosphate ;.-. . 2 grams 



Ammonium lactate (neutral) . .' . . . . . . 6 grams 



Commercial asparagin . . . . . . ... . . 4 grams 



Aq. dest . . . ..... . 1000 c.c. 



Add enough caustic soda solution to make the reaction faintly 

 alkaline, distribute to tubes and sterilize by the discontinuous method. 

 Winogradsky's Solution for Nitrifying Microorganisms. 



Sulphate of ammonium 1 gram 



Sulphate of potassium 1 gram 



Dissolve in distilled water 1000 c.c. and add a previously sterilized 

 solution of magnesium carbonate. Distribute to tubes or flasks and 

 sterilize for three days by fractional method for periods of twenty 

 minutes each. 



Winogradsky's Culture Medium for Bacteria which Oxidize Nitrites 

 into Nitrates. 



Sodium nitrite, C. P. /. . . . . . ....'. 1.0 gram 



Potassium phosphate . 0.5 gram 



Magnesium sulphate ... ... . , . . . . 0.3 gram 



Carbonate of soda (dry) . . . . f .. . . ... 1.0 gram 



Chloride of sodium . . . . . 0.5 gram 



Sulphate of iron . . ..... . . .... 0.4 gram 



Distilled water . *. . ... .... ... .' 1000 c.c. 



This fluid also forms the base of a 1.5 per cent, agar medium. 

 Nitrate Solution. 



Sodium chloride, C. P V . . 0.5 gram 



Dry peptone . . w * . . >- 1.0 gram 



Potassium nitrate, C. P. . . . . . . '. . . . 0.2 gram 



Distilled water . ....... 1000 c.c 



