CYTOLYSINS 125 



bated at 55 C. for fifteen to twenty minutes, during which period it 

 is shaken several times. The mixture is centrif uged and the supernatant 

 fluid placed in a separatory funnel with five to ten volumes of ether 

 and shaken for one or two hours until the solution becomes quite 

 colorless. The saccharose solution is separated from the ether and 

 dialyzed in running water in order to free it from sugar and salt. 

 After dialyzation the solution is concentrated in a vacuum until it 

 reaches the original volume of blood serum employed. Strong salt 

 solution may prevent amboceptor from entering into combination with 

 complement, but it does not interfere with the amboceptor cell union. 

 Alkalis may prevent either form of union and may serve partly to 

 dissociate amboceptor cell combinations. 



Mechanism of Operation of the Amboceptor. As has been 

 pointed out previously, the action of amboceptor is differently inter- 

 preted by the Ehrlich and the Bordet schools. If the Ehrlich view of 

 the two-fold binding group is to be adhered to, it should be possible to 

 show on the one hand a combination with antigen, and on the other 

 a combination with complement. Of these possibilities there is no 

 doubt that combination with cells is possible, but as yet no conclusive 

 evidence has been produced to show a combination between comple- 

 ment and an amboceptor not united to its antigen. The discovery of 

 the Neisser-Wechsberg phenomenon (see page 147) was regarded as 

 demonstrating a combination between free amboceptor and comple- 

 ment. This explanation, however, does not take into account the 

 possible relationship to certain colloidal reactions such as have been 

 described in connection with the inhibition zone of strong agglutinins 

 and is therefore not to be regarded as settled. Ehrlich and Morgen- 

 roth stated that if amboceptor is repeatedly injected into animals an 

 anti-amboceptor is produced which serves to combine with the cytophilic 

 group of amboceptor, but Bordet found that a normal serum, free from 

 hemolytic amboceptor could be used to produce the same immune body, 

 and argued therefrom that this antibody could not be regarded as a 

 specific receptor. Ehrlich and Sachs admitted the fact of Bordet's 

 experiments and came to the conclusion that the substance is anti- 

 complementophile, rather than anti-cytophile. As will readily be seen 

 this argument presupposes the correctness of the Ehrlich conception 

 of amboceptor, and is therefore not to be accepted as conclusive. With- 

 out the actual demonstration of the union of free amboceptor and 

 complement, the union of antigenic cells and amboceptor is of quite as 

 much value in support of the Bordet view of sensitization as in support 

 of the Ehrlich hypothesis. Nevertheless, Ehrlich and Sachs have 

 reported what they believe to be a crucial experiment in that it appears 

 to show that at least in some instances free amboceptor and comple- 

 ment may combine. Horse serum is slightly hemolytic for guinea-pig 

 erythrocytes and ox serum is somewhat more so. If inactivated ox 

 serum and fresh horse serum are added to guinea-pig cells, hemolysis 

 occurs, the ox scrum acting presumably as an amboceptor, the horse 

 serum as complement. If the guinea-pig cells are treated with inac- 



