8o 



Scientific Proceedings (32). 



Just as I had finished my experiments Tschernogubow 

 published an article in which he stated that he successfully 

 employed an antihuman amboceptor in combination with human 

 complement. As he made no statement as to the source and 

 strength of his antihuman amboceptor no judgment can be made 

 on his method. It is rather striking to observe that the amount 

 of the amboceptor he employed was 0.25 c.c. for each tube, in 

 contrast to 0.002 in my method. It may not be entirely out of 

 place to mention here some essential reasons why I use guinea- 

 pig's serum as complement. 



According to my observations the amount of complement in 

 human serum varies considerably in different individuals. In the 

 majority of specimens o. I to 0.03 c.c. of the fresh serum contain 

 about enough complement to produce complete hemolysis with 

 ten units of the amboceptor, while the same quantities do not cause 

 any marked hemolysis when two units of the amboceptor are 

 employed. Thus ten units of the amboceptor are to be used as a 

 necessary amount for utilizing human serum as complement. 

 Now in regard to the quantity of each specimen of human serum 

 to be used for complement it is essential to determine the exact 

 strength by a preliminary titration, because if we use some excess of 

 complement the test turns out completely negative. It appears 

 probable that human complement, like that of the rabbit, is not 

 very sensitive to the fixing action of the antigen-antibody of 

 syphilis. In this respect guinea-pig's complement is excellent 

 The method which Tschernogubow recommended is to collect a 

 few drops of a patient's blood in saline solution and use the sus- 

 pension both for the complement and corpuscles at the same time. 

 But, this does not permit one to make any estimation of the 

 complement content of the blood. Moreover, there is no direct 

 way of ascertaining whether any inhibition which may be observed 

 with a given specimen is due to the anticomplementary property 

 of antigen alone or to the combined action of the antigen and 

 syphilis antibody, because the complement and antibody exist in 

 the same serum side by side, if this latter is present at all. Again 

 the relying upon human complement makes impossible the testing 

 of any specimen of blood which has been allowed to stand for 

 several days, as the activity of complement rapidly diminishes and 



