The Hemolytic Amboceptor '295 



reverse the conditions of the test. Thus, if we should desire to know 

 how much variation thefe may be in the complements from different 

 animals under different conditions of age, feeding, health, etc., we 

 can now do so by determining whether, when i cc. 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 manipulation, 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 Wassermann 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 experi- 

 menters 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 comple- 

 ment fixation, it would result in positive readings where the final 

 result should be negative. To overcome this possibihty, they dif- 

 ferentiate 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 wUl 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 hemo- 

 lysis is merely the relative 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 com- 

 plement and by i unit of amboceptor as by 20 units of amboceptor 

 and 0.1 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 propor- 

 tional action by any excessive addition of amboceptor, but simply to 

 increase the latter sufficiently to provide for the accidental presence, 

 in the serum to be tested, of substances affecting hemolysis. Fortu- 

 nately, means are provided for controlling this action, as will be 

 shown below. 



The amboceptor serum keeps indefinitely. When it is to be kept 

 and used from time to time, many experimenters prefer , to seal 

 it in a number of small tubes, one of which is opened when the 

 serum is needed, the remainder being kept in an ice-box. Others 

 prefer a stoppered bottle that can be opened and a measured quan- 

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



