64 GENERAL BACTERIOLOGY 



CHAPTER II 

 PHYSIOLOGY OF BACTERIA 



EXERCISE 37. PEEPAEATION OF SPECIAL MEDIA. 



The following media will be necessary for the work outlined in 

 this chapter : 



a. DEXTROSE BOUILLON. To ordinary bouillon add \% dextrose 

 (c. P.), tube and sterilize in steamer, not in autoclave, 7 test-tubes 

 and 2 fermentation tubes. 



&. DEXTROSE GELATIN. \% dextrose (c. P.), tube and sterilize 

 in steamer, 6 tubes. 



c. DEXTROSE AGAR. \% dextrose (c. P.), tube and sterilize in 

 steamer, 5 tubes. 



d. LACTOSE AGAR. \% lactose (c. P.), tube and sterilize in 

 steamer, 2 tubes. 



e. LITMUS SOLUTION. To 10 gms. of the dried material add 500 

 cc. of distilled water, digest in a warm place, decant clear liquid and 

 add a few drops of nitric acid to produce a violet color. (Button.) 

 Place in flasks or test-tubes and sterilize in steamer three times, 1 

 tube. 



/. DEXTROSE-FREE BROTH. This is prepared from beef by inocu- 

 lating the meat infusion with an organism capable of fermenting 

 sugar, such as B. coli, and allowing it to stand several hours at 38 C. 

 (Between &. and c. Exercise 4.) The bouillon is then prepared in 

 the usual manner. 1 



Or DUNHAM'S SOLUTION. 



Sodium chloride 0.5 gm. ) _. ., ., n . -,. , , ,, 



.__. . f Boil until all is dissolved, filter, 



Peptone (Witte) 1. gm. V .,. . , , 



' _ _ f tube and sterilize, 4 tubes. 



Water 100. gms. ) 



g. NITRATE SOLUTION. 



1 Smith: Jour. Exp. Med., 1897, 2: 543. 



