326 Wassermann Reaction for Diagnosis of Syphilis 



conditions of age, feeding, health, etc., we can now do so by 

 determining whether, when i c.c. of the corpuscles, i unit 

 of amboceptor and varying quantities of complementary 

 serums are combined, any variation in the final results will 

 obtain. 



Or, if we desire to know to what extent the sheep corpuscles 

 may change through prolonged keeping or other manipula- 

 tion, it can be done by maintaining the unit of amboceptor 

 and the unit of complement and adding larger or smaller 

 quantities of the corpuscles. 



The conditions under which the unit of amboceptor is 

 titrated constitute the standard conditions of the Wasser- 

 mann reaction. In it are always employed i unit of sheep 

 corpuscle suspension, i unit of complement, and i unit of 

 amboceptor. Here, however, a slight difference of opinion 

 is reached, it being argued by many experimenters that such 

 exact proportions may make the test uncertain, because, 

 should there be the slightest tendency on the part of the 

 remaining reagents to inhibit hemolysis by means other 

 than complement fixation, it would result in positive readings 

 where the final result should be negative. To overcome this 

 possibility, they differentiate between the amboceptor 

 unit and the amboceptor dose, the latter being commonly 

 twice and sometimes four times the unit. 



Now, though the amboceptor unit is determined by the 

 method given, it by no means follows that those proportions 

 are the only ones that will lead to hemolysis. By increasing 

 the amboceptor we can diminish the complement with the 

 same end-result, a matter that has been graphically shown 

 by Noguchi,* who says " that hemolysis is merely the rela- 

 tive expression of the combined action of amboceptor and 

 complement, and is not the absolute indication of the amount 

 of the hemolytic components present in the fluid. The 

 same amount of hemolysis can be produced by i unit of 

 complement and by i unit of amboceptor as by 20 units 

 of amboceptor and o.i unit of complement or any other 

 appropriate combination of these two components." 



As in the performance of the test we work always with 

 i unit of complement, we do not want to unduly disturb its 

 proper proportional action by any excessive addition of am- 

 boceptor, but simply to increase the latter sufficiently to pro- 

 vide for the accidental presence, in the serum to be tested, 

 * "Serum Diagnosis and Syphilis," 1910, p. 13 et seq. 



