PRODUCTION OF ANTITOXINS FOR THERAPEUTIC PURPOSES 235 



fections. They are prepared by immunizing horses with carefully 

 graded and increasing doses of the respective toxins until the serum of 

 the animals shows a sufficiently high antitoxin content, after prelim- 

 inary trials, to warrant more extensive bleeding. Large quantities of 

 blood are then collected aseptically by puncturing the jugular vein. 

 The serum is carefully separated and standardized according to an ac- 

 cepted technic, in order to determine the antitoxin content in units. 

 A small amount of preservative is added, and the serum is finally dis- 

 pensed in special containers or syringes ready for administration. In 

 some laboratories it is customary to precipitate the globulin fraction of 

 the serum with magnesium or ammonium sulphate, and redissolve the 

 portion containing most of the antitoxin in saturated sodium chlorid 

 solution. The bulk of the serum is thus greatly decreased, and ob- 

 jectionable constituents largely eliminated, to the obvious advantage 

 of the preparation for therapeutic purposes. 



Antitoxins have also been prepared for other bacterial toxins, as 

 those of the dysentery bacillus (Kruse-Shiga) and Bacillus botulinus, 

 for the vegetable toxins in pollen, and for the animal toxins in snake ven- 

 oms. 



There are other serums for the treatment of certain infections, which 

 depend for their effects chiefly upon the presence of bacteriolysins and 

 immune opsonins, and these are described in a subsequent chapter. 



THE PRODUCTION OF DIPHTHERIA ANTITOXIN 



The following, taken largely from Park, is a widely used and ac- 

 cepted technic for the production of diphtheria antitoxin: 



Production of the Diphtheria Toxin. A strong diphtheria toxin 

 should be obtained by growing a virulent culture in a 2 per cent, nutri- 

 ent peptone bouillon made from "bob" veal, of an alkalinity that should 

 be about 9 c.c. of normal soda solution per liter above the neutral point 

 to litmus, and prepared from a suitable peptone (Witte). The broth 

 should be poured into large-necked Erlenmeyer flasks in comparatively 

 shallow layers, so as to allow of the free access of air, and maintained at a 

 temperature of about 35 to 36 C. (Fig. 71). 



In the Hygienic Laboratory of the Public Health and Marine-Hos- 

 pital Service "Smith's bouillon" is used for preparing the toxin. This 

 is made of fresh lean beef, after the muscle sugar and all other sugars 

 have been removed by fermentation with a good culture of Bacillus coli. 

 The reaction is adjusted until 0.5 per cent, acid to phenolphthalein, that 

 is still distinctly alkaline to litmus, and 1 per cent, peptone, 0.5 per cent. 



