Physiology. — “On the formation of heterogenetic antigen by 
combination of hapten and protein”. By K. LANDSTEINER 
(Communicated by Prof. C. H. H. Spronck). 
(Communicated at the meeting of November 26, 1921). 
In former communications,*) which also contain references of the 
literature on the subject, the author came to the conclusion, that 
the peculiar properties of heterogenetic antigen very likely can be 
explained as follows. 
These antigens consist of two different parts, one an alcohol 
soluble part (perhaps of lipoid nature) aud one a protein. The 
alcohol soluble-part has the property of reacting specifically in vitro, 
but is devoid of antigenic properties (similar substances have been 
called by the author hapten) whereas only the entire complex (hapten 
+ protein) acts as an antigen. Since that time, the same opinion 
has been expressed by TaniGucnt. ®) 
Tue author deemed it desirable to confirm this view by direct 
proof and therefore he undertook to investigate whether it would 
be possible to obtain an artificial antigen bycombining the hapten 
with a protein which as such contains no beterogenetic antigen. 
It was doubtful at the onset whether this endeavour would be 
successful, since similar phenomena are not yet known. The experi- 
ment however gave positive results. Hach of 5 groups of rabbits 
was injected intraperitoneally with one of the following substances. 
1. Pig serum ten times diluted with 0,9 percent saline. 
II. Alcoholic-extract of 15 gr. horse kidney emulsified with 100 
c.c. 0,9 percent of saline. 
UL. As I, but heated for a 4 hour at 80° C. 
IV. The extract of horse kidney emulsified with ten times diluted 
pig-serum. 
V. As IV but heated for a 4 hour at 80° C. 
The rabbits were injected with 5 e.c. of these solutions six times, 
5 Meeting of the “K. Akad. v. Wetensch. te Amsterdam” of Februari 26, 
1921. Biochem. Zeitschr. 119. 294 (1921). 
2) Journ. of Path. a. Bact. 24. 253, 254. Juli 1921. 
16 
Proceedings Royal Acad. Amsterdam. Vol. XXIV. 
