850 EXPERIMENTAL INFECTION AND IMMUNITY 



EXERCISE 29. AMBOCEPTORS AND COMPLEMENTS (Continued) 

 EXPERIMENT 74. ROLE OF AMBOCEPTOR AND COMPLEMENT IN HEM- 

 OLYSIS 



1. Prepare a 2>^ per cent, suspension of washed sheep corpuscles. Bleed a 

 healthy guinea-pig under ether anesthesia, separate the serum, and dilute 1 : 20 with 

 normal salt solution (complement). Secure antisheep hemolytic serum (inactivated) 

 whose hemolytic titer is known (consult instructor). 



2. Proceed to set up a series of four test-tubes as follows: 



Tube 1: 1 c.c. corpuscle suspension + sufficient normal salt solution to make the 



total volume about 4 c.c. 

 Tube 2: 1 c.c. corpuscle suspension +1 c.c. complement serum (1:20)+ sufficient 



salt solution. 

 Tube 3: 1 c.c. corpuscle suspension + two hemolytic doses of antisheep hemolysin 



+ salt solution. 

 Tube 4: 1 c.c. corpuscle suspension +1 c.c. complement serum + two doses of 



hemolysin + salt solution . 



3. Shake each tube gently and incubate at 37 C. for one or two hours. 



(a) In which tube has hemolysis occurred? Explain the results. 



(b) What does inactivation of a serum mean? 



(c) Could some hemolysis occur, using the complement serum and 

 corpuscles without immune hemolysin? 



EXPERIMENT 75. SPECIFICITY OF AMBOCEPTORS 



1. Prepare a 2^ per cent, suspension of washed sheep corpuscles and a 1 per 

 cent, suspension of washed human corpuscles. Bleed a guinea-pig under ether, 

 separate serum, and dilute 1:20 with normal salt solution. Secure antisheep and 

 antihuman hemolytic serums (inactivated) whose hemolytic titers are known. 



2. Proceed as follows: 



Tube 1: 1 c.c. sheep corpuscles+1 c.c. complement (l:20)+two doses of anti- 

 sheep hemolysin + salt solution up to 4 c.c. 



Tube 2: 1 c.c. sheep corpuscles+1 c.c. complement (l:20)+five doses of anti- 

 human hemolysin. 



Tube 3: 1 c.c. human corpuscles+1 c.c. complement (l:20)+two doses of anti- 

 human hemolysin. 



Tube 4: 1 c.c. human corpuscles+1 c.c. complement (l:20)+five doses of anti- 

 sheep hemolysin. 



Tube 5: 1 c.c. sheep corpuscles+3 c.c. salt solution (control). 



Tube 6: 1 c.c. human corpuscles+1 c.c. salt solution (control). 



3. Shake tubes gently and incubate for an hour or two. 



(a) In which tubes has hemolysis occurred? 



(b) What does this experiment teach as to the specificity of these 

 amboceptors? 



(c) Discuss the specificity of hemolytic and bacteriolytic ambo- 

 ceptors. 



