44 



LABORATORY COURSE IN SERUM STUDY 



To each tube add 1 unit (0.1 c.c.) of cells previously sensitized with 

 1 unit of amboceptor. 



Calculate the concentration of complement in the tubes used in the 

 preliminary complement titration, and compare the results. If the 

 activity of complement does depend upon the concentration, complete 

 laking should occur in one hour in those tubes of the second series 

 which contain a dilution of guinea pig serum equal to that in the first 

 tube of the first series which showed complete haemolysis. 



Experiment 2 



THE ACTIVITY OF SENSITIZER OR AMBOCEPTOR DEPENDS ON ITS 

 TOTAL AMOUNT AND NOT ON ITS CONCENTRATION 



Suspend 1 unit (0.05 of 25%) of cells in varying amounts (1, 5, 10, 

 20 c.c.) of salt solution. 



To each tube add 1 unit of amboceptor. 



Mix and keep at 37 C. for one half hour. 



Centrifugalize. 



To the sediment in each tube add 1 unit of complement, as previously 

 determined, and sufficient salt solution to bring the volume to 1 c.c. 



Incubate. 



All tubes should show complete haemolysis in 1 hour if the cells 

 have absorbed the entire unit of amboceptor. 



Each student needs: 



2 c.c. of 25% sheep cells 1 ten-c.c. pipette 



(about) 2 c.c. of undiluted com- 2 test tube racks for 12 J-inch 



plement test tubes 



25 units of amboceptor 20 J-inch test tubes 



Flask of saline 1 fifty-c.c. centrifuge tube 



4 one-c.c. pipettes 3 fifteen-c.c. centrifuge tubes 



6 -inch test tubes 



