THE MANUFACTURE AND USE OF SERA AND VACCINES. 



4. Concentrated Diphtheric Antitoxin. 



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While the chemical nature of antitoxin is not known, it has been deter- 

 mined that it is united, in some way, with the globulins of the blood. The 

 attempts to isolate antitoxin have resulted in the manufacture of a refined or 

 concentrated antidiphtheric serum which is used quite extensively though 

 it does not meet with the unqualified favor accorded the antidiphtheric 

 serum. The process of manufacture is as follows: 



Fig. 60.— Container with diphtheria antitoxin, supplied with hypodermic needle, piston, 

 all ready for immediate use by the physidan. The plunger is simply a homeopathic vial 

 with rubber stopper. {Cutter Laboratory.) 



A. The antidiphtheric serum is saturated with ammonium sulphate 

 which precipitates the globulins (containing the antitoxin) in the form of a 

 white mass. It is then filtered and the filtrate rejected. 



B. The precipitate left on the filter is redissolved in water and this solu- 

 tion is again treated with ammonium sulphate as in (a). The object in 

 redissolving in water is to wash the globulins. 



