METHODS FOR CONDUCTING THE SYPHILIS REACTION 437 



than the anticomplementary dose, and well within the range of safety 

 against non-specific complement fixation. If 10 tests are to be made, 

 then at least 4.4 c.c. of diluted antigen are required, including sufficient 

 for the antigen control, or in round numbers, 0.5 c.c. of antigen plus 4.5 

 c.c. of salt solution in order to secure the maximum turbidity slowly added. 



5. Serum. Serum should be fresh and clear and heated in a water- 

 bath to 55 C. for half an hour before using. The temperature should 

 not go above 56 C. nor below 55 C. The complement in perfectly 

 fresh serum is usually inactivated at this temperature within fifteen 

 minutes, but it is better to adopt the period of one-half hour as a 

 routine, especially in removing heat-sensitive anticomplementary sub- 

 stances that develop in serums more than a day old. Dose, 0.1 c.c., 

 or if the serum is perfectly fresh, 0.2 c.c. may be used. 



6. Cerebrospinal Fluid. This should be fresh and free from blood. 

 It is used unheated, as spinal fluid contains little or no hemolytic 

 complement. The dose should be at least four times that of the 

 serum, or from 0.4 to 1 c.c. 



The Test. A front and a rear tube for each serum are placed in a 

 rack. Each tube is marked plainly with the patient's name or in- 

 itials, and in addition the front tube is marked with the number of 

 the antigen or with the letter "A, " or the word " antigen" is written 

 on it, the rear tube being marked "control" (serum control). The 

 necessity for carefully marking each tube is nowhere more important 

 than in conducting Wassermann reactions with a number of serums, 

 as the slightest error or lapse of memory may result in confusion and 

 prove to be quite a serious matter. 



In each series of reactions the serum from a known case of syphilis 

 that has given a positive reaction and the serum of a known non- 

 syphilitic person are included as positive and negative controls re- 

 spectively. 



Into each front tube the proper dose of antigen is placed; to the 

 front and rear tubes 0.1 c.c. of the patient's serum is added. (If 0.2 

 c.c. is being used as the dose, this amount should be placed in both 

 tubes.) To all tubes 1 c.c. of the complement (1 : 20) and sufficient 

 normal salt solution are then added to bring the total volume in each 

 to about 3 c.c. 



The rear tube of each set is the serum control; the positive and 

 negative serums are treated in just the same manner as the patient's 

 serum. In addition to these there are three other important controls 

 that should not be omitted: 



