182 LABORATORY COURSE IN SERUM STUDY 



Materials : 



2 agar slants of staphylococcus aureus. 

 Sterile saline solution. 

 Sterile pipette. 



Sterile tube or bottle with glass beads. 

 Haemocytometer. 



Thionin solution in 1 per cent phenol. 

 Glass slides. 

 Wright or Jenner stain. 

 Phenol. 



LESSON XXXII 

 ANAPHYLAXIS 



INTRODUCTORY REMARKS 



BECAUSE of the large number of animals required in this work, 

 the class had better do these experiments in relatively large 

 groups. 



I. ACTIVE SENSITIZATION 



Four guinea pigs of about 200 grams weight are etherized on operat- 

 ing boards for intravenous injection into external jugular veins. 



Guinea pigs (a) and (b) receive 0.25 c.c. horse serum diluted with 

 1.75 c.c. salt solution. 



Guinea pigs (c) and (d) receive 0.25 c.c. sheep serum diluted with 

 1.75 c.c. salt solution. 



This should be done two weeks before the time for Lesson XXXII. 



Two weeks after the sensitizing injection the pigs are again injected 

 intravenously as follows, into opposite jugular vein : 



(a) 0.5 c.c. of horse serum. 

 (6) 0.5 c.c. of sheep serum, 

 (c) 0.5 c.c. of sheep serum. 



The results in (a) and (c) demonstrate anaphylactic shock. 

 The absence of symptoms in (b) demonstrate specificity. 



Guinea pig (d) is given 0.01 c.c. sheep serum subcutaneously four 

 times, at one hour intervals. Observe carefully symptoms after each 

 injection. Then give 0.5 c.c. sheep serum intravenously. Symptoms 

 will be slighter than in (a) and (c). This demonstrates desensitization. 



