112 LABORATORY COURSE IN SERUM STUDY 



LESSON XIX 



WASSERMANN REACTION 1 



I 



PREPARATION OF THE ANTIGEN 



THE general principles of the technique of the Wassermann 

 reaction are the same as those of other forms of complement 

 fixation already discussed with one notable exception: the 

 antigen is not specific in origin, i.e., is not made from Spirochseta 

 pallida or (as it originally was) from syphilitic organs. Land- 

 steiner and his successors found that equally good or better re- 

 sults could be obtained with lipoidal substances extracted from 

 normal organs by means of alcohol and other lipoid solvents. 

 Various lipoid mixtures are now used, the most serviceable being 

 alcoholic extracts of normal heart muscle, usually beef, guinea 

 pig, or human heart. Sometimes cholesterin is added to the al- 

 coholic extract. The alcoholic solution, of course, is well diluted 

 with saline solution before use. These facts, empirically ascer- 

 tained since the introduction of the Wassermann reaction, show 

 definitely that this test is not dependent upon an antigen- 

 antibody union as is the case with other forms of complement 

 fixation. 



No matter what lipoid antigen is used, its specificity and dos- 

 age have to be determined by careful preliminary titrations and 

 by trial on known syphilitic and non-syphilitic sera before it can 

 be used in diagnostic work. 



As the preparation of antigen for use in the Wassermann test 

 takes time it had better be begun about three weeks before the 

 antigen is needed for the experiments below. The preparation 

 of three typical and useful antigens will be described. The class 

 should be divided into three groups of students and each group 

 of students should be made jointly responsible for the prepara- 

 tion of one or two specimens of one of the types of antigen. 



1 Lessons XIX and XX should be repeated if possible, an entire week 

 given to them. 



