934 EXPERIMENTAL INFECTION AND IMMUNITY 



(f) Does complement keep for three days? 



(g) Is it possible to remove the thermostabile anticomplementary 

 action of a serum? Could such a serum be used in a complement-fixa- 

 tion reaction? How is this condition of the serum detected? 



(h) Under what conditions is a serum likely to become anticomple- 

 mentary in action? Is a sterile serum likely to become anticomple- 

 mentary? 



EXERCISE 37. "WASSERMANN REACTION (Continued) 

 EXPERIMENT 89. WASSERMANN REACTION (FIRST METHOD) 



1. Secure four specimens of blood: one from a known syphilitic person; the 

 second from a known normal person, the third and fourth specimens for diagnosis. 

 Also a specimen of cerebrospinal fluid. 



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 90. 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? 



