134 BACTERIOLOGY 



manufacture of antitoxins and other biological products. 

 This serum, obtained under aseptic precautions, has ob- 

 viously an advantage, and has in our hands proven entirely 

 satisfactory for routine work. 



In either case the serum is to be decanted into clean, 

 sterile test-tubes provided with cotton plugs, after which 

 it must be immediately sterilized. For this purpose the 

 method suggested by Councilman and Mallory is now 



FIG. 19 



Chamber for sterilizing and solidifying blood serum. (Koch.) 



generally used. It is as follows: Place the test-tubes con- 

 taining the serum in a slanting position in a dry air sterilizer 

 and heat them to from 80-90 C. for a time necessary 

 to solidify the serum. After this they are kept for twenty 

 minutes on three successive days in the steam sterilizer at 

 100 C. They should be kept at room temperature between 

 the exposures to the steam. After this treatment the serum 

 should be sterile. 



