938 EXPERIMENTAL INFECTION AND IMMUNITY 



(c) Which is the more liable to error in technic? 



(d) Discuss the applicability of the complement-fixation technic to 

 the differentiation of proteins in general, as animal, vegetable, and bac- 

 terial proteins. 



EXERCISE 48, VENOM HEMOLYSIS 

 EXPERIMENT 10i. VENOM HEMOLYSIS IN SYPHILIS 



1. Secure 1 c.c. of venom solution 1: 1000. 



2. Secure four specimens of blood (for technic see page 408) from cases of late 

 secondary or tertiary syphilis and one specimen of normal blood. Also a known 

 normal blood for a control. 



3. Prepare the subdilutions of venom and conduct the tests after the technic 

 described on page 409. 



(a) Discuss the prevailing views regarding the mechanism of venom 

 hemolysis. 



(b) Discuss the value of the venom test in the diagnosis of syphilis. 



(c) Discuss the main points in the technic. 



EXERCISE 49. BACTERIOLYSIS 

 EXPERIMENT 102. PFEIFFER BACTERIOLYTIC TEST 



1. Secure 1 c.c. of serum from a rabbit which has been immunized with typhoid 

 bacilli. By working with cholera and a highly potent serum better results are secured, 

 but as there is probably more danger connected with the handling of cholera cultures, 

 typhoid may be substituted with fairly good results. Inactivate by heating to 56 

 C. for half an hour. 



2. Prepare a twenty-four-hour-old agar culture of a suitable strain of Bacillus 

 typhosus. 



3. Prepare a 1 : 100 dilution of the immune serum and place 3 c.c. in a small test- 

 tube. Add three loopfuls of culture and emulsify thoroughly. Inject a guinea-pig 

 intraperitoneally with 2 c.c. of the emulsion. 



4. At intervals of ten, twenty, forty, and sixty minutes withdraw small amounts 

 of exudate and study bacteriolysis; prepare hanging-drop preparations which may be 

 compared with a similar control on the culture; prepare smears of the culture and 

 peritoneal exudate and stain with carbol-thionin or carbolfuchsin. 



5. If desirable, the bacteriolytic titer of the serum may be determined after the 

 method given in the text. 



(a) Describe the phenomenon of bacteriolysis. 



(b) Are bacteriolysis and hemolysis similar processes? Give the 

 source of complement in this reaction. 



(c) Discuss the specificity of bacteriolytic reactions. 



(d) Discuss the practical value of the bacteriolytic test in the diag- 

 nosis of a microorganism. 



