858 EXPERIMENTAL INFECTION AND IMMUNITY 



2. Conduct a Wassermann reaction with each serum after the first method, 

 using an antigen of alcoholic extract of syphilitic liver. 



(a) Record your results. In case the hemolytic system control was 

 not completely hemolyzed, what may be the reasons and what influence 

 would this result have on interpreting the reactions? 



(b) In case the antigen control was not completely hemolyzed, what 

 influence would this result have on the reactions? 



(c) If a serum control were incompletely hemolyzed, what influence 

 would this have on the results of the test? 



(d) Is this method a quantitative reaction? 



(e) What is the nature of the antibody in a syphilitic serum? 



(f) How are these reactions recorded? How should they be re- 

 ported to a clinician? 



(g) Discuss the value of the Wassermann reaction in the various 

 stages of syphilis as a guide to treatment. 



EXERCISE 38. WASSERMANN REACTION (Continued) 

 EXPERIMENT 89. WASSERMANN REACTION (SECOND METHOD) 



1. Conduct a Wassermann reaction with each of five specimens of serum after 

 the second method, using an alcoholic extract of syphilitic liver, an extract of acetone- 

 insoluble lipoids, and an alcoholic extract of heart reenforced with cholesterin. One 

 of these serums should be from a syphilitic person (positive control) and one from a 

 normal person (negative control). 



(a) What are the advantages of using more than one antigen? 



(b) Discuss the relative value of these three antigens. 



(c) Under what conditions may a cholesterinized extract be used? 



EXERCISE 39. WASSERMANN REACTION (Continued) 

 EXPERIMENT 90. WASSERMANN REACTION (THIRD METHOD) 



Conduct a Wassermann reaction with each of four specimens of serum after 

 the third method, using an extract of acetone-insoluble lipoids. One of these serums 

 should be a positive control and one a normal or negative control. 



What is the advantage of using a quantitative test? 



EXERCISE 40. WASSERMANN REACTION (Continued) 

 EXPERIMENT 91. WASSERMANN REACTION (FOURTH METHOD) 



Conduct a Wassermann reaction with a known positive, a known negative, 

 and two unknown serums after the fourth method, using an alcoholic extract of 

 syphilitic liver. 



What are the main advantages of this technic? 



