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TECHNIQUE OF THE COMPLEMENT FIXATION METHOD 



The hemolysin is prepared as follows: its titer for example is i : 2000 and it is em- 

 ployed in the dilution of i : 1000. Each tube except the blood and complement tubes 

 will receive i c.cm. of the diluted hemolysin; i c.cm. of the latter if diluted properly 

 would give 1000 c.cm.; o.i of the hemolysin which is the smallest amount that can be 

 measured will give 100 c.cm. Every tube except 28 to 30 will receive i c.cm. of the 

 hemolysin dilution i : 1000. Tubes 29 and 30 will receive none (replaced by saline), 

 tube 28 will receive 1/2 c.cm. of the hemolysin and 1/2 c.cm. of saline. 



After an hour's incubation, each tube receives i c.cm. of R. B. C. and i c.cm. of 

 the hemolysin just mentioned. If it is desired to hasten the results, it is advisable 

 to mix a sufficient equal quantity of R. B. C. and hemolysin solution (30 c.cm. of each) 

 and allow the mixture to remain in the incubator for a short time before the hour's 

 incubation is up. Then instead of adding i c.cm. of these ingredients separately, 

 2 c.cm. of the mixture is added to all except tubes 28 to 30. Tubes 29 and 30 receive 

 i c.cm. of blood and i c.cm. of saline and tube 28 i c.cm. of blood, 1/2 c.cm. of 

 hemolysin and 1/2 c.cm. of saline. 



Meier's Modification. 



For over a year G. Meier in Wassermann's laboratory has been using a turbid sus- 

 pension of the syphilitic liver instead of the clear antigen as prepared above. After 

 the liver is cut up into fine pieces, placed into four times its weight of one-half per cent, 

 carbolic acid solution in normal saline and shaken for 24 hours, the mixture is filtered 



I (Qualitative Test) 



1 o. 4 c.cm. of luetic serum frequently binds complement of its own accord. Experience has 

 shown that if o. 2 c.cm. does not bind complement and o. 2 c.cm. of serum + 0.2 c.cm. of anti- 

 gen does bind complement, the unknown serum is surely of luetic origin. 



