SERUM DIAGNOSIS 



469 



and a suspension of sheep corpuscles.* The serum from each 

 guinea pig should be titrated in the following manner before 

 it is used. A basic dilution of 1-10 is made of the comple- 

 ment by adding 0.3 cc. of the complement to 2.7 cc. of salt 

 solution in a test tube. 



TABLE NO. III. 



TITRATION OF COMPLEMENT. 



a. 0.9% NaCl solution. 



b. Guinea pig serum in diminishing quantities. 



c. Of previously titrated hemolytic serum, double dissolving 

 quantity. 



d. 5% suspension of washed sheep blood corpuscles in salt solu- 

 tion. 



From this dilution certain definite amounts are added to 

 each of five other tubes according to Table III. To the com- 

 plement thus distributed to each tube, is added 1 cc. of hemo- 

 lytic amboceptor of which the titre has already been deter- 



* The serum is obtained by bleeding a strong vigorous guinea 

 pig by cutting the throat. The pig is first anesthetized and the 

 ventral portions of the neck shaved and disinfected. The blood is 

 collected preferably in a Petri dish. 



