182 A MANUAL OF BACTERIOLOGY 



alexin. x According to Ehrlich's view, whether it be normal 

 or " immune " serum (i.e. serum of a treated animal), 

 bacteriolysis or haemolysis takes place only when the 

 complement and amboceptor unite (Fig. 33, p. 175), 

 complement by itself having little affinity for the bacterium 

 or erythrocyte, the combination forming the " lysin," 

 which then acts. According to Gruber, however, neither 

 bacteriolysin nor hsemolysin exist as a chemical entity, 

 the specific bacteriolytic or hsemolytic action being due 

 to the fact that the cells first absorb the amboceptor and 

 so become accessible to the complement, for the two 

 substances do not combine in definite proportions the 

 more the blood- corpuscles are laden with the amboceptor 

 the smaller the quantity of complement required to bring 

 about their solution. 



Many bacteria e.g. B. pyocyaneus, B. typliosus, staphy- 

 lococci and streptococci produce hsemolysins, and the 

 haemoglobin staining occurring in septic diseases, etc., is 

 probably partly due to the action of bodies of this nature 

 elaborated by the infecting organisms. 



Practical Uses of Haemolysis, etc. 



1. Haemolysis test. Some micro-organisms produce non-specific 

 hsemolysins, others do not ; this may constitute a difference between 

 allied organisms. For instance, as a rule true cholera vibrios do 

 not haemolyse, while many cholera-like vibrios do. The test can be 

 applied in two ways : (a) Defibrinated rabbits' blood may be mixed 

 with melted agar cooled to 45 C. The mixture is poured into Petri 

 dishes, allowed to set, and when cool inoculated with the organism 



1 As previously stated (p. 175), numerous complements undoubtedly 

 exist, yet bacteria will absorb both bacteriolytic and haemolytic com- 

 plements. Bordet and Gengou suppose that while a particular ambo- 

 ceptor has a maximum avidity for its homologous complement (which 

 may be termed dominant), it is also able to take up other " non- 

 dominant " complements, and thus bacteriolytic amboceptor is able to 

 absorb both bacteriolytic (dominant) and hsemolytic (non-dominant) 

 complements. 



