NUTRIENT CULTURE-MEDIA 75 



Hiss' Medium for Plating 



Agar 15 gm. 



Gelatin 15 " 



Meat extract 5 " 



Sodium chlorid 5 " 



Dextrose 10 " 



Distilled water 1000 c.c. 



Digest agar in autoclave, then add the other ingredients, 

 except dextrose, which is added to the cleared and filtered 

 product. No neutralization is necessary. Tube in regular 

 way. For tube cultures this medium is modified by using 

 agar 5 gm. and gelatin 80 gm. in place of the quantities given 

 above. A careful titration is made and the reaction adjusted 

 to 1.5 per cent, acid by adding HC1. After filtration, dex- 

 trose is added, then tubed and sterilized. 



Hesse's Medium for Typhoid 



Agar 5gm. 



Peptone 10 gm. 



Extract of beef 5 " 



Sodium chlorid 8.5 " 



Water 1000 c.c. 



Digest agar in 500 c.c. water, add the other ingredients 

 dissolved in water. Mix and filter. Adjust reaction to i 

 per cent, acid, tube, and sterilize in autoclave. 



Bile Salt Agar (MacConkey's) 



Sodium taupocholate 0.5 part 



Peptone 1.5 parts 



Lactose 3.5 " 



Agar.... 1.5 " 



Water q. s. 100.0 " 



Agar and peptone dissolved first. Lactose and bile salt 

 added before tubing. Sterilize on three days intermittently. 



