138 MEDICAL BACTERIOLOGY 



PART II-MEDICAL BACTERIOLOGY 

 CHAPTER VI 



PATHOGENIC AEROBES 



EXERCISE 74. PREPARATION OF CULTURE MEDIA. 



The following media will be necessary for the work outlined in 

 the following chapters. This is exclusive of a few special media 

 which are described under special heads and are to be made as a 

 part of the exercises in which they are used. 

 100 tubes of agar. 



12 tubes of dextrose agar. 

 100 tubes of gelatin. 



12 tubes of dextrose gelatin. 



30 tubes of bouillon. 



10 fermentation tubes of dextrose bouillon. 



35 tubes of potato. 



35 tubes of litmus milk. 



35 tubes of dextrose free broth or Dunham's solution. 



30 water blanks. 



30 tubes of Loeffler 's blood serum. This is prepared as follows : 

 a. Collection of the blood. Sterilize Mason fruit jars, by suc- 

 cessive washings in corrosive sublimate, distilled water, alcohol and 

 ether (or a large pail may be used). These are to be carried to 

 the slaughter house and the blood from a beef caught directly into 

 them. The blood is then allowed to stand undisturbed for 15 to 

 30 minutes, or until the clot has firmly attached itself to the sides 

 of the vessels, when they are to be covered and removed to the 

 laboratory. 



6. Separation of the serum from the blood clot. The clot is 

 separated from the sides of the vessel by means of a sterile knife or 

 glass rod, and the vessel placed in the ice chest. After standing 

 48 hours the clot will have shrunken away from the walls of the 



