7S8 TOXINS, TOXOIDS, AND ANTITOXINS 



of saturated sodium chloride will precipitate all the antitoxin, and the albumen present will 

 remain in solution. This is filtered after three hours' standing. The first precipitate of 

 euglobulin is taken up in water of twice the volume of the original plasma, again saturated 

 with sodium chloride, and filtered. To this second filtrate "B" saturated ammonium sulphate 

 solution is added up to 35 per cent. The resulting precipitate and solution of salt is filtered 

 through the papers containing the precipitate from filtrate "A." The precipitate is pressed 

 and dialyzed free of ammonium sulphate and salt. This dialyzed product need not be stored 

 as there will be no separation of insoluble substances. The methods given are applicable to 

 all the antitoxins in horse serum. 



With other animals the methods of concentration must take cognizance of the differing 

 antitoxin distribution in the globulins. For instance, in goat serum about one-third of the 

 antitoxin is in the pseudoglobulin fraction and two-thirds with the euglobulin fraction.' 



' Banzhaf, E. J., and Famulener, L. W.: Coll. Studies, Bureau of Lab. Dept. of Health, New York 

 City, 8, 208. 1914. 



