84 MICROBIOLOGY 



Preparation of acid glycerin bouillon. This is prepared 

 either as ordinary bouillon or as a sugar free bouillon, with 

 the omission of the alkali and the addition of 5% c. p. glycerin. 



Preparation of glucose bouillon. Take the desired 

 quantity of sugar-free peptonized bouillon and add 1% of 

 pure grape sugar (glucose). After it is dissolved and thor- 

 oughly disseminated through the bouillon by stirring or pour- 

 ing, distribute the bouillon in fermentation tubes, filling com- 

 pletely the closed branch and the open bulb about half full. 

 It is often used in small test tubes. Sterilize by discontinu- 

 ous steaming for 20 minutes each day for 3 consecutive 

 days. The tubes should be wiped, labeled and stored until 

 needed for use. 



Preparation of lactose bouillon. This is prepared by 

 adding 1% of pure lactose (milk sugar) to the peptonized 

 sugar-free bouillon. It is necessary that the bouillon used 

 does not contain muscle sugar. After adding the lactose, 

 which has been dissolved and thoroughly mixed in a few- 

 cubic centimeters of the bouillon, distribute in fermentation 

 tubes and small test tubes, sterilize, label and store. 



Preparation of saccharose bouillon. This is peptonized 

 sugar-free bouillon to which \% pure saccharose (cane sugar) 

 has been added. It is prepared from bouillon free from 

 muscle sugar in the same manner as lactose bouillon. 



Calcium carbonate broth. This medium has been 

 recommended for obtaining mass cultures of streptococci. 

 It is prepared by taking 100 cc. of bouillon and adding 1% 

 powdered calcium carbonate and 1% of glucose. It is recom- 

 mended to sterilize the calcium carbonate in a hot air sterilizer 

 before adding it to the bouillon. 



Peptone solution (Dunham's). This is a 1 or 2 per cent 

 solution of peptone in tap or distilled water to which 0.5 per 

 cent of sodium chloride is added. The peptone and sodium 

 chloride are dissolved by heating. The fluid is filtered, placed 

 in tubes and sterilized. The reaction is slightly alkaline to 

 litmus which is suitable for the growth of most bacteria. It 

 can be altered or standardized if desired. 



