42 



LABORATORY COURSE IN SERUM STUDY 



Each student needs: 

 10 c.c. of 5% sheep cells 

 2 c.c. amboceptor (diluted 1-100) 

 2 c.c. complement undiluted, for each three students 

 1 test tube rack 

 20 half-inch test tubes 

 4 1-c.c. pipettes, and flask salt solution 

 4 f -inch test tubes 



LESSON V 



QUANTITATIVE RELATIONS OF AMBOCEPTOR AND COMPLE- 

 MENT (Continued) 



Experiment 1 



THE ACTIVITY OF COMPLEMENT DEPENDS TO SOME EXTENT ON ITS 

 CONCENTRATION AND NOT ONLY ON THE TOTAL AMOUNT PRESENT 



A 25 per cent suspension of washed sheep cells is made. 



A series of tubes is set up (if necessary by instructor) in which the 

 minimal amount of amboceptor necessary to lake 0.1 c.c. of these cells 

 in the presence of 0.05 c.c. of undiluted complement and in a total volume 

 of 1.0 c.c. is determined. The hsemolytic serum (amboceptor) is then 

 diluted so that this minimal amount is contained in 0.1 c.c. 



The student then mixes 2.0 c.c. of this amboceptor dilution with 

 2.0 c.c. of the 25 per cent red cell suspension. He then determines, in 

 the following preliminary titration, the minimal amount (unit) of com- 

 plement which will lake 0.1 c.c. of these cells in one hour, in a total 

 volume of 1 c.c. 



Then with 1, 5, and 10 times this minimal amount in the tubes as indi- 

 cated in the protocol the experiment is set up. The protocol given 

 below is constructed on the supposition that, in the above titration, 0.2 

 c.c. of a 1 to 10 dilution of complement was the smallest amount of the 

 complement which gave complete laking. 



