COMPLEMENT FIXATION IN GONOCOCCUS INFECTIONS 503 



suits indicating either that this scarlet fever streptococcus belonged 

 to the common group of streptococci or that the complement-fixation 

 test was a group reaction. In a similar study of the diphtheria group 

 of bacilli I 1 found that the pseudodiphtheria bacillus could not be differ- 

 entiated from other members of the group by complement-fixation 

 reactions indicating its relationship to the true diphtheria bacillus; 

 similar studies made by Williams, Raiziss, and I 2 with the typhoid 

 colon group of bacilli, by Craig and Nickols 3 with several strains of 

 spirochetes, by Cooke 4 with acid-fast bacilli, by Olmstead 5 and Woll- 

 stein 6 with meningococci, by Hooker 7 with typhoid bacilli, and by 

 Hitchens and Brown 8 with streptococci indicate that the bacterio- 

 lytic amboceptors are highly specific and yield highly specific reac- 

 tions with proper technic, and particularly with good and sensitive 

 antigens, and under these conditions the complement-fixation test 

 may be more delicate in differentiation than agglutination or other 

 immunity reactions. As a practical procedure, however, the comple- 

 ment-fixation technic is too intricate and time-consuming. In this con- 

 nection I desire to direct particular attention to the possibility of the sera 

 of normal rabbits yielding positive complement-fixation reactions with 

 various bacterial and lipoidal extracts as discussed on page 1+19, in con- 

 ducting complement-fixation tests with rabbit or dog sera the serum of each 

 animal should first be tested with the antigen and immunization conducted 

 only in case the animal's serum is found to react negatively; subsequent 

 complement-fixing properties of the serum may then be ascribed to the pres- 

 ence of specific amboceptors. 



COMPLEMENT FIXATION IN GONOCOCCUS INFECTIONS 



This was one of the first infections to be studied by means of 

 the complement-fixation technic, but the results secured were not 

 generally satisfactory until it was shown that the antigen must be 

 polyvalent. 



1 Jour. Infect. Dis., 1912, 11, 44. 



2 Jour. Infect. Dis., "1913, 13, 321. 



3 Jour. Exper. Med., 1912, 16, 336. 



4 Jour. Amer. Med. Assoc., 1917, Ixviii, 1504. 



5 Jour. Immunology, 1916, 1, 307. 



e Jour. Exper. Med., 1914, 20, 201. 



7 Jour. Immunology, 1916, 1, 1. 



8 Personal communication. 



