Xin. IMMUNIZING EXPERIMENTS WITH ERYTHRO- 

 CYTES LADEN WITH IMMUNE BODY. 1 



By Dr. HANS SACHS, Assistant at the Institute. 



THE interesting experiments of v. Dungern 2 have furnished 

 further proof that the same group (receptor) of the blood-cells which 

 in haemolysis combines with the specific immune body causes the 

 production of this immune body within the organism, v. Dungern 

 injected rabbits with ox blood to which a plentiful amount of an 

 immune body (obtained from rabbits by immunizing with ox blood) 

 had been added, and found, as was to be expected, on the basis of 

 the side-chain theory, that animals so treated failed to produce 

 any immune body whatever. 



The results of the investigations of M. Neisser and Lubowski 3 

 show that the complete inactivity of such saturated receptors 

 agglutinated typhoid bacilli in the animal body is not at all a general 

 rule, but that, on the contrary, a moderate development of the 

 immunity reaction occurs even with such mixtures and that this 

 depends on certain individual differences. Hence at the suggestion 

 of Prof. Ehrlich I have extended the experiments of v. Dungern 

 and undertaken blood-immunization experiments on a large series 

 of animals. The results obtained lead to certain modifications of 

 von Dungern's conclusions. 



The method of these experiments must be guided by two prin- 

 ciples. To begin, it is important that the receptors of the injected 

 blood are really saturated, for even a very slight free residue might 

 effect an immunity reaction in the animal body. And yet it is es- 

 sential to remove any possible excess of immune body, because this 



1 Reprint from the Centralblatt fur Bacteriologie, Parasitenkunde und In- 

 fection Krankheiten, Vol. XXX, 1901, No. 13. 



2 v. Dungern, Muench. med. Wochenschr., 1900, No. 20. See also page 56. 

 3 See the preceding article, page 146. 



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