104 



LABORATORY COURSE IN SERUM STUDY 



Experiment 2 



PRELIMINARY DETERMINATION OF THE NON-SPECIFIC BINDING POWER 

 OF THE IMMUNE SERUM 



1 Serum from rabbit immunized to typhoid bacilli. This serum should be heated 

 to 55 for 30 minutes on day of using. 



Follow same procedure as directed under Experiment 1. 



Experiment 3 



Use that amount of typhoid suspension which is next below the 

 amount which was found to not interfere at all with the hsemolytic action 

 of the complement. Also take that amount of serum which lies next 

 below the amount which did not interfere with haemolysis. Let us say 

 there was full haemolysis in Tube 3 of the first set and 2 of the second; 

 we set up the third as follows : 



Add sufficient saline solution to bring the final total up to 2.5 c.c. 

 and incubate 1 hour in water bath. Add 0.5 c.c. of 5% red cell suspen- 

 sion and two units of amboceptor to each tube and incubate 30 minutes. 



Tubes 2 and 3 are necessary control tests in all complement fixation 

 work, to prove that under the precise conditions under which comple- 

 ment is fixed in Tube 1 it is not fixed by antigen alone or by antiserum 

 alone. 



Materials for each student: 



13 half-inch test tubes. Test tube rack. 



4 large test tubes. 

 24 hour typhoid culture. 

 Platinum loop. 



6 one-c.c. pipettes. 

 1.5 c.c. immune antityphoid serum (diluted). 



7. c.c. 5 per cent sheep cell emulsion. 

 4.0 c.c. 10 per cent guinea-pig serum. 

 30 units amboceptor. 

 Salt solution. 



