GENERAL TECHNIC 435 



reaction depends upon removing the excess of indifferent and inhibiting 

 serum components and upon the destruction or diminution of the natural 

 antisheep amboceptor present in so large a percentage of human 

 serums. As Noguchi and Bronfenbrenner have pointed out, this method 

 may likewise remove the antibodies concerned in the reaction. To 1 c.c. 

 of heated serum add 3.5 c.c. of saline solution and 0.5 c.c. of a 7 per cent, 

 suspension of freshly precipitated barium sulphate; shake, and let it 

 stand for one hour at 37 C.; centrifugalize, and pipet off the diluted 

 serum, which is now ready to be tested (1 c.c. = 0.2 c.c. of undiluted 

 serum). 



Cadaver serums are likely to be highly discolored with hemoglobin 

 and quite anticomplementary. Such serums may be tested in half the 

 usual dose, and while the results are quite specific, they are not so reliable 

 or constant as those obtained from the living. 



The doses of serum used in testing for the syphilis reaction are given 

 with each method. In the original Wassermann test 0.2 c.c. was used. 

 As a rule, from 0.05 c.c. to 0.2 c.c. of serum are satisfactory; higher doses 

 may occasionally show a stronger positive reaction, but the serum must 

 be perfectly fresh to avoid non-specific complement fixation, and the 

 natural antisheep amboceptor should first be removed. 



(b) Cerebrospinal Fluid. In certain nervous diseases the cerebro- 

 spinal fluid is examined for the syphilis reaction. Fluid is secured by 

 lumbar puncture, according to the method described on p. 37. If the 

 specimen contains blood, it should be centrifuged until it is clear. It 

 should not be heated before use, as it does not contain hemolytic comple- 

 ment, and fresh fluids from cases other than syphilitics do not react pos- 

 itively. Cerebrospinal fluids, as a rule, possess weaker deviating powers 

 than the corresponding blood-serum, and hence it is necessary to use 

 larger doses at least 0.5 to 1 c.c., instead of 0.05 to 0.2 c.c., as in the 

 case of blood-serum. 



(c) Other Fluids. Positive syphilitic reactions have been described 

 as occurring with milk, pleural and peritoneal exudates, and albuminous 

 urine (Bauer and Hirsh) from luetic cases. The reactions with these 

 substances are conducted in the same manner as with Cerebrospinal 

 fluid. The material should be perfectly fresh, as anticomplementary 

 action is likely to occur. 



II. Complement. While complement is to be found in the fresh 

 normal serum of practically all warm-blooded animals, not all are 

 suitable for complement-fixation tests. A suitable complement must 

 possess two important properties: (1) Complementary activities, or 



