THE TECHNIQUE OF SERUM REACTIONS 



269 



4. Is like three, except that antigen is omitted. 



If this modification is used at all (and its value is by no means 

 established), a fifth control should be added in which known syphilitic 

 serum is used. 



These tubes are exposed to 37.5° C. for one hour, at the end of which 

 time 1 c.c. of a 5 per cent emulsion of sheep's corpuscles are added. 



If the test is positive, tube one should be without hemolysis, as well 

 as the fifth control with known syphilitic serum. Tubes two, three. 



SCHEME FOR WASSERMANN TEST. 



ADAPTED TO ORIGINAL WASSERMANN SYSTEM AFTER SCHEME OF NOGUCHI. 



O = test tube. ' 



Place in water bath at 40° C. for one hour, then add to all tubes red blood cells and 

 amboceptor. These are previously mixed so that 2 c.c. contains the equivalents of 

 1 c.c. of a 5 per cent emulsion of sheep corpuscles and 2 units of amboceptor. Again 

 expose to 40° C. If the serum tested is positive, tubes 1 and 3 should show no 

 hemolysis, all the other tubes showing complete hemolysis in one hour. 



and four, on the other hand, should show complete hemolysis. This 

 modification of the Wassermann test has not found universal adoption 

 and is little ysed at present. 



