METHODS FOK CONDUCTING THE SYPHILIS REACTION 459 



first, by the serum and antigen alone, and second by these two sub- 

 stances combined. The complement absorbed is measured in terms 

 of hemolytic doses. This method consumes a little more time and 

 more of the various reagents is required. It is, nevertheless, the 

 best quantitative method we have, and shows exactly the degree of 

 complement fixation in each case. 



In conducting any complement-fixation test the following are 

 essential factors if success is to be achieved: (1) Reliable reagents, 

 particularly a good antigen must be had, for no matter how much 

 care is exercised, good results cannot be secured with indifferent 

 reagents; (2) the observer must possess a thorough working under- 

 standing of the underlying principles and particularly of the quanti- 

 tative relations of the various reagents; (3) there must be an accurate 

 adjustment of the hemolytic system; (4) he must have a careful, 

 painstaking and accurate habit of pipeting small amounts. Accuracy 

 should never be sacrificed for speed, as the latter is properly acquired 

 only with experience. 



TECHNIC OF THE FIRST METHOD 

 THE ORIGINAL WASSERMANN REACTION 



This is the original Wassermanri reaction, except that an alcoholic, 

 instead of an aqueous extract of syphilitic liver, is used as antigen. 

 This is the simplest of all technics, and, when properly performed, con- 

 stitutes, in the final analysis, a reliable test and one especially adapted 

 for those not constantly engaged in this work. 



1. Complement. Fresh clear serum (not over twenty-four hours 

 old) of a healthy guinea-pig. Dilute 1 : 10 by adding 9 c.c. of sterile 

 normal saline solution to each 1 c.c. of serum. Dose, 1 c.c. (= 0.1 c.c. 

 of undiluted. serum). 



2. Corpuscles. Sheep's blood washed three times and diluted to 

 make a 5 per cent, suspension. For example, 1 c.c. of corpuscles in 

 19 c.c. of salt solution makes up sufficient for a number of tests. 



3. Hemolytic Amboceptor. Serum of a rabbit immunized with 

 washed sheep's corpuscles. As stated elsewhere, this serum is heated 

 to 55 C. for half an hour, and an equal part of chemically pure glycerin 

 is added. Mix well and preserve in sterile 1 c.c. ampules. Each am- 

 pule will, therefore, contain 0.5 c.c. of serum. One stock dilution is 

 prepared in such manner that about 0.2 c.c. represents one hemo- 

 lytic dose. One may otherwise prepare a whole series of flasks with 

 various dilutions, and in making a titration to use 1 c.c. of each di- 



