WASSERMANN REACTION 933 



(c) Why are these titrations so important? 



(d) In a complement-fixation test what would be the result if the 

 antigen were used in the anticomplementary dose? What would be 

 the result if the antigen were used in less than the antigenic dose? 



(e) What constitutes a satisfactory antigen for any complement-fix- 

 ation test? 



(f ) In conducting a diagnostic reaction, should the antigen be used 

 in exactly one antigenic dose or double or treble this amount? Why 

 and under what conditions would this be a safe procedure? 



(g) Why should the antigen be diluted slowly with salt solution? 

 (h) Why is a serum control so important in these titrations? What 



other controls are used and why? 



(i) Which is more important, the anticomplementary or antigenic 

 titration and why? 



EXERCISE 36. WASSERMANN REACTION 

 EXPERIMENT 88. ANTICOMPLEMENTARY ACTION OF SERUMS 



1. Secure 1 c.c. of five different specimens of human serums which have been 

 standing in the laboratory for one, two, four, six, and ten days respectively. The 

 last specimen should be intentionally infected with a culture of staphy loco ecus. 



2. Divide each serum into two portions and heat portion "B" to 56 C. for half 

 an hour. 



3. Place 0.2 c.c. of each specimen (unheated) in a series of five test-tubes. 



4. Place 0.2 c.c. of each specimen (heated) in a second series of five test-tubes. 



5. To each tube add 1 c.c. of complement 1:20 and sufficient salt solution to 

 bring the total volume to 3 c.c. Shake gently and incubate for half an hour. Add 

 1^ units of amboceptor and 1 c.c. corpuscle suspension to each tube and incubate 

 for one hour. 



6. A hemolytic system control (complement, corpuscles, and amboceptor) should 

 be included; also a corpuscle control. 



(a) Record your results. Are any of the serums anticomplementary? 

 How do you determine this? 



(b) What is meant by the terms anticomplementary action of a serum? 



(c) What significance has this phenomenon in complement-fixation 

 work? 



(d) Are anticomplementary bodies thermolabile or thermostabile? 

 May both exist? Under what conditions are each most likely to be 

 present? 



(e) How are thermolabile anticomplementary bodies removed or 

 their influence overcome? When a serum is three or more days old, 

 what is the chief object of heating it before it is used in a complement- 

 fixation test? 



