APPLICATION OF COMPLEMENT FIXATION 199 



THE WASSERMANN TEST 



The results of the Wassermann test are usually indicated by plus signs ; the 

 following diagram indicates the interpretation of the results: 



DEGREE OF HEMOLYSIS 

 WITH 

 0.2 c.c. human serum o.i c.c. human serum 



Result 



P.H. 



P.H. 

 CH. 

 C.H. 



++ 



+ 



In these readings the partial hemolysis is relatively small in amount. If 

 with 0.2 c.c. human serum the hemolysis is well advanced without being complete 

 and is complete with o.i c.c. serum, the result is indicated by the sign +. Other 

 symbols are used, but the results are indicated in the same general way. 



Reference to the protocol shows that the serum in tubes I, '2, 3, 4 is positive 

 for syphilis and would be signified as a three plus (H h+) serum. The known 

 positive is a four plus (++++) and the known negative reacts properly. Tubes 

 13 and 14 show that the antigens are not antilytic, and tubes 16, 17, 18 show that 

 the sera are not antilytic. Tube 18 shows that the hemolytic system operates 

 properly. Tube 19 shows that the hemolysin does not produce hemolysis with- 

 out complement, and tube 20 shows that the corpuscles do not hemolyze without 

 the other agents. 



The quantities given in the protocol are based on a unit of i.o c.c. to simplify 

 the explanation. In order to save reagents the quantities are usually divided in 

 half, so as to be on a 0.5 c.c. basis. The directions for the United States Army 

 in France called for quarter quantities, so as to save reagents. The latter direc- 

 tions also call for half saturation of the alcoholic heart extract with cholesterol 

 (0.2 per cent.). Bronfenbrenner has suggested the use of o.i c.c. amounts of the 

 reagents. Methods of measuring by drops have been employed, but are inaccurate 

 because of the possible variation in the size of drops unless a stalagmometer or 

 similar instrument is employed. 



