STANHOPE BAYNE- JONES 765 



FLOCCULATION WITH DIPHTHERIA TOXIN AND ANTITOXIN 



The reports of the number and results of the flocculation titrations of diphtheria 

 toxin and antitoxin are not sufficiently detailed for statistical analysis. It may be in- 

 ferred from available data that satisfactory agreements between animal and floccu- 

 lation tests have been obtained with about 90 per cent of the toxins and antitoxins 

 used. The discrepancies which have been observed, together with the significance of 

 the results in general, have been noted in preceding paragraphs. A value within 10 

 per cent of the results of animal tests can be expected from flocculation reactions with 

 most sera and toxins. The method has given useful information to those engaged in the 

 production of diphtheria toxin and antitoxin, and contrary to results reported by 

 Zingher (1924-25), most investigators, dealing with toxoids and anatoxins, have 

 found the flocculation values of these modified toxins a useful guide in choosing im- 

 munizing agents in diphtheria. Rapidly flocculating toxins with high Lj values have 

 been found to be the most efficacious antigens after modification by formaldehyde, 

 and antitoxins with a high speed of flocculation may be found to possess especially 

 valuable curative properties. With diphtheria toxin and antitoxin, the flocculation 

 method has given results of practical utility and, as described in previous sections of 

 this review, has provided a new means for the study of these substances. 



SCARLATINAL STREPTOCOCCUS TOXIN AND ANTITOXIN 



The application of the Ramon flocculation method to the titration of scarlatinal 

 streptococcus toxin and antitoxin has given useful results for the standardization of 

 these products (Dyer [1925] and Povitzky [1925]). Povitzky has used the method at 

 the laboratories of the Health Department of New York City to follow antitoxin pro- 

 duction in horses during immunization against scarlet fever streptococcus toxin and 

 to measure the potency of this toxin. In the manuscript of her report, which Dr. 

 Povitzky has allowed me to see before its publication, she records a satisfactory cor- 

 respondence between the results of the flocculation tests and of skin tests in chfldren. 

 She found that the following conditions were essential for the successful result of the 

 test: 



(i) A streptococcus toxin standardized for the number of toxic skin doses per cubic 

 centimeter by the Dick test in children. The toxin should be made by growth of the organism 

 in a medium without blood. Phenol, added in crystals to give a concentration of 0.3 per cent, 

 may be used as a preservative. (2) A constant amount of toxin and varying amounts of serum 

 gave best results. For weak sera, 0.5 cc. of toxin was used; for strongly antitoxic sera, i cc. 

 of toxin was used in each tube. (3) The optimum temperature was found to be 37° C. Temper- 

 atures above this inhibited the flocculation. Flocculation usually occurred in 12 to 18 hours, 

 but occasionally appeared only after 24 to 48 hours. 



Scarlatinal streptococcus toxin was not flocculated by diphtheria antitoxin, anti- 

 pneumococcus serum, or by an antibacterial streptococcus serum. Some specimens 

 of streptococcus antitoxin flocculated with diphtheria toxin. This was thought to be 

 related to the natural diphtheria antitoxin in the blood of some horses. Flocculation 

 in mixtures of tetanus toxin and scarlatinal streptococcus antitoxin may be explica- 

 ble on a similar basis, 



Povitzky found no relationship between the agglutinin content of the antitoxic 



