WASSERMANN AND OTHER COMPLEMENT FIXATION TESTS 257 



suspension of gonococci vigorously for 15 minutes or longer and adding 0.25 per 

 cent, tricresol; keep in full dark containers in ice box. 



.The amount of salt solution used to wash off the growth and suspend it is 

 such that the contained bacteria make it slightly cloudy or turbid. The method 

 of standardization and titration is the same as previously described for Wasser- 

 mann antigen except that one-half the minimum anticomplementary quantity 

 is taken for the unit, the amount to be used in making tests. The value of a 

 gonococcus antigen depends to a considerable degree upon its being polyvalent 

 including half a dozen or more strains of gonococci; this, together with the 

 difficulty of culturing the organism, compels most serologists to depend upon 

 some distributing laboratory for their supply. I have found the gonococcus 

 antigens marked by Parke, Davis & Co., and H. K. Mulford Co. as good as 

 any and superior to most. 



The complement fixation test is a valuable aid in the diagnosis of echino- 

 coccus infestations; the filtered fluid from an echinoccus cyst, to which 0.25 

 per cent, of tricresol has been added, is used for antigen. 



The detection of glanders and epidemic abortion of cattle is largely done by 

 complement fixation tests. 



Early discovery of active tuberculosis is one of the most important and 

 difficult tasks of the physician. All available methods of investigating these 

 cases are frequently inadequate. A test that can disclose the nature of the 

 disease a short time after it becomes active, before serious permanent injury 

 has been effected and will indicate subsidence of the disease will supply one 

 of the greatest aids for further study and control of tuberculosis. The evidence 

 accumulated during the last 5 years seems to indicate that such a test will be 

 developed in the near future, and that it will be a complement fixation test. It 

 has been well established that a demonstrable quantity of specific amboceptor 

 is present in the blood serum of a large per cent, of patients in the early stages 

 of pulmonary tuberculosis, a satisfactory antigen for routine clinical examina- 

 tions has not yet been made, when this is done complement fixation tests in the 

 diagnosis of tuberculosis will take a place as important as the Wassermann holds. 



BIBLIOGRAPHY 



The serum reactions described in this brief work are a very small portion of 

 the subject of immunity. The best understanding of these reactions and their 

 significance requires some knowledge of the subject in general. 



Any attempt to present so complicated a subject to students, in a brief 

 time, so they can master technique that will be available in diagnosis, must be 

 to some degree dogmatic and, therefore, lacking the broadest discussions and 

 presentation of facts desirable. With this in mind, the student inspired with 

 true scientific thought is most earnestly solicited to read other books and mono- 

 graphs relative to the subject, especially those tabulated: 



"Studies in Immunity," Ehrlich-Bolduan, 2d edition, John Wiley & Sons, New York. 

 Deutsch. med Wchnschr., 1906, xxxii, 745 (original Wassermann monograph). 

 17 



