1 86 PRACTICAL METHODS IN IMMUNITY 





of antigen which will by its antigenic power alone fix complement or, 

 as is often stated, be anticomplementary. 



Then use one-half this amount as the antigen content for the test. 



The method of Noguchi, as previously described, but using one-half the anticom- 

 plementary dose of antigen, is satisfactory after experimenting with the proper 

 amount of inactivated serum of the patient to be examined. 



For the Gonococcus fixation test it is most important to have antigen 

 prepared from a mixture of several strains of gonococci, preferably 

 10 or 12. 



In our laboratory we have had sharper and more satisfactory readings by employ- 

 ing the Emery technic, placing in the first antigen tube an emulsion containing 

 4,000,000,000 organisms to the c.c. 



It is also satisfactory to have the antigen in tube i so concentrated that it will 

 prove anticomplementary. Tube 2 would contain one-half this amount of antigen; 

 tube 3, one-fourth; tube 4, one-eighth; tube 5, one-sixteenth; tube 6, one-thirty-second; 

 tube 7, one-sixty-fourth. Some sera are strong enough in specific gonococcus anti- 

 body to bring about complement fixation in tube 8. Along with the test of the 

 patient's serum we should carry out tests with known negative and positive sera. 



DETERMINATION OF OPSONIC POWER AND THE PREPARATION 

 OF VACCINES 



In that which has been considered in the previous pages only the 

 theories of Ehrlich have been brought out. In order to understand the 

 problems involved in the study of opsonins the phagocytic theory of 

 immunity brought forward by Metchnikoff must be studied. Ehrlich's 

 views would seem to hold with diseases where there is an increase in 

 bacteriolytic or antitoxic power of the serum while in such diseases, as 

 are caused by pathogenic cocci, the pjiagocvtic element js operative as 

 there is an absence of bacteriolvtic power in the serum of the person 

 with the infection. 



There are two kinds of phagocytes, the microphages (represented by the poly- 

 morphonuclears) which on phagolysis or disintegration give off microcytase, a 

 bactericidal substance. Cytase is the same as complement or alexine. 



The microphages are chiefly bactericidal while the macrophages, represented by 

 the large mononuclears of the blood and fixed connective-tissue cells^exert their 

 action on protozoa or animal cells. . 



(t) 



Phagocytes may either act by m^estin^ j^cteria and destroying 



them intracellulary or they may as a result of phagolysis bring about 

 bacteriolysis exr.ra.r.p.11n1a.rlv. According to Metchnikoff the intra- 



