468 



THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



1. One antigen is employed, either an alcoholic extract of syphilitic 

 liver or acetone-insoluble lipoids. The same general rule as to dosage 

 is employed, namely, from two to four times the titrated antigenic 

 unit, providing these amounts are not more than one-fourth the 

 anticomplementary dose. 



2. 0.6 c.c. of each serum is heated to 55 C. for half an hour and 

 diluted 1 : 10 by adding 5.4 c.c. of salt solution. 



3. Fresh guinea-pig serum complement is diluted 1 : 20 as usual, 

 and used in doses of 1 c.c. ; sheep corpuscles are ma.de up in a 2.5 per 

 cent, suspension and used in doses of 1 c.c.; antisheep amboceptor is 

 adjusted to the complement and corpuscles by a method of titration, 

 as given with the first method, and used in a dose equal to 2 hemo- 

 lytic units. 



The Test. Eight test-tubes are arranged in a row and the first 

 marked with the patient's name; in each of the first seven tubes the dose 

 of antigen is placed. The following amounts of diluted serum (1 : 10) 

 are then added : 



First tube: 

 Second tube: 

 Third tube: 

 Fourth tube: 

 Fifth tube: 

 Sixth tube: 

 Seventh tube 

 Eighth tube: 



0.1 c.c. serum diluted 1 

 0.2 c.c. serum diluted 1 

 0.4 c.c. serum diluted 1 

 0.6 c.c. serum diluted 1 

 0.8 c.c. serum diluted 1 

 1.0 c.c. serum diluted 1 

 2.0 c.c. serum diluted 1 

 2.0 c.c. serum diluted 1 



10 = 0.01 c.c. serum. 

 10 = 0.02 c.c. serum. 

 10 = 0.04 c.c. serum. 

 10 = 0.06 c.c. serum. 

 10 = 0.08 c.c. serum. 

 10 = 0.1 c.c. serum. 

 10 = 0.2 c.c. serum. 

 10 = 0.2 c.c. serum (control). 



The eighth tube contains no antigen, and is the serum control with 

 the maximum dose employed. 



In testing cerebrospinal fluid the following doses may be used (undi- 

 luted): 0.1 c.c., 0.2 c.c., 0.4 c.c., 0.6 c.c., 0.8 c.c., 1 c.c., 1.5 c.c., and 

 1.5 c.c. for the eighth or control tube. 



To each tube 1 c.c. of the diluted complement (1 : 20) is now added, 

 and sufficient salt solution to bring the total volume in each up to 3 c.c. 



Controls. Unless one is examining a large number of serums and 

 is sure that the antigen is satisfactory, known positive and negative 

 serum controls may be included in the series. As a general rule, 

 however, they should not be omitted. 



The hemolytic system control receives at this time 1 c.c. of the 

 complement dilution and 2 c.c. of salt solution. The antigen control 

 receives the dose employed plus 1 c.c. of complement and sufficient 

 salt solution to bring the total volume up to 3 c.c. The corpuscle 



