METHODS FOR CONDUCTING THE SYPHILIS REACTION 471 



Thomsen, 1 the syphilis reaction becomes quite delicate and accurate, 

 but is more complicated than the other methods, and should not be 

 attempted until one is accustomed to the simpler test and thoroughly 

 understands the underlying principles of the syphilis reaction and knows 

 the many sources of fallacy. The greater amount of work that it en- 

 tails and the larger quantities of complement-serum and amboceptor 

 that are required may serve as factors against its adoption as a routine 

 method. On the other hand, the sources of error are well under control, 

 and the test has yielded remarkably uniform results in the hands of my 

 colleagues in their respective laboratories, working with the serums 

 of the same persons. 



The technic as given here has been worked out and tested with a 

 large number of sera by Matsunami, Brown, Meine and I in an effort 

 to evolve a standardized Wassermann reaction. Every phase of the 

 Wassermann reaction has been studied specifically by experiment and 

 the following technic is based upon these results: 



1. Corpuscles. Sheep corpuscles are washed three times with salt 

 solution and made up in a 2J per cent, suspension; dose, 0.5 c.c. 



2. Hemolysin. Antisheep hemolysin is titrated by placing increas- 

 ing amounts of diluted serum, as 0.1 c.c., 0.15 c.c., 0.25 c.c., 0.30 c.c., 

 and 0.35 c.c. of a 1 : 300 dilution in a series of test-tubes and adding 

 to each tube 0.025 complement serum (= 0.5 c.c. of a 1 : 20 dilution), 

 0.5 c.c. of 2J per cent, corpuscle suspension, and sufficient salt solution 

 to make the total volume in each tube about 3 c.c. Each tube is gently 

 shaken and incubated in the water-bath at 38 C. for one hour, when the 

 reading is made. The unit of hemolysin is the smallest amount giving 

 complete hemolysis. Instead of using increasing amounts of one di- 

 lution of hemolysin as above, a series of dilutions may be made in flasks, 

 as 1 : 2000; 1 : 2500; 1 : 3000; 1 : 3500; 1 : 4000, etc., and 1 c.c. of each 

 used in the titration. 



The unit need not be determined more than once in two weeks, 

 providing the hemolysin is kept at a low temperature. 



3. Complement. It is advisable to use the mixed sera of at least 

 two or more healthy guinea-pigs. When only a small amount of com- 

 plement serum is required, sufficient blood may be obtained by aspirat- 

 ing 2 c.c. of blood from the hearts of several large animals (see page 41). 

 The complement serum should be clear, collected a few hours before use, 

 and preferably from fasting animals. The mixed serum is diluted 

 with 9 parts of normal salt solution (1 : 10) and titrated. This titra- 



1 Ztschr. f. Immunitatsf., orig., 1910, 7, 389. 



