860 EXPERIMENTAL INFECTION AND IMMUNITY 



EXERCISE 43. <X)NOCOCCUS COMPLEMENT-FIXATION REACTION 

 EXPERIMENT 95. TITRATION OF GONOCOCCUS ANTIGEN 



1. Secure 1 c.c. of gonococcus antigen and dilute 1:10 by adding 9 c.c. normal 

 saline solution. 



2. Secure 1 c.c. of an antigonococcus serum or the serum of a person who reacts 

 positively and inactivate. 



3. Conduct an anticomplementary and antigenic titration as described on page 

 479. 



4. A similar titration may be conducted with glanders antigen and antiserum. 



(a) Give three methods of preparing a bacterial antigen. 



(b) Is it advisable to make polyvalent antigens and why? 



(c) Which is of more practical value, the anticomplementary or anti- 

 genic titration and why? 



(d) What part of the anticomplementary dose of an antigen may be 

 safely used in a diagnostic test? 



(e) Is it advisable to titrate a bacterial antigen at frequent intervals? 



EXERCISE 44. GONOCOCCUS COMPLEMENT-FIXATION REACTION 

 EXPERIMENT 96. TECHNIC OF THE GONOCOCCUS REACTION 



1. Secure six specimens of serum from a genito-urinary clinic, particularly of 

 men suffering with chronic gonococcus infections. Also a known positive and a 

 known normal serum for controls. 



2. Conduct the reactions after the method described on page 478. 



(a) Is the gonococcus reaction specific? 



(b) Is complement fixation in bacterial infections likely to be as well 

 marked as in syphilis? 



(c) In what cases of gonococcus infection is the reaction likely to be 

 negative? Likely to be positive? 



(d) How soon after infection is the reaction likely to become posi- 

 tive? 



(e) Discuss the practical value of the gonococcus complement-fixation 

 test. 



EXERCISE 45. GONOCOCCUS COMPLEMENT-FIXATION TEST 

 EXPERIMENT 97. TECHNIC OF THE GONOCOCCUS REACTION 



1. Using a similar set of serums as in the preceding experiment, conduct the 

 reactions with the one-tenth technic as described on page 481. 



(a) What is the main advantage of this technic? 



(b) By which method are the reactions more easily read and re- 

 corded? 



