128 



LABORATORY COURSE IN SERUM STUDY 



Each student needs: 



One known syphilitic serum. One normal serum. 

 7 c.c. of 10% complement. 20 |-inch test tubes. 



Five f-inch test tubes. Racks. 10 one-c.c. pipettes. 



LESSON XXI 

 COMPLEMENT FIXATION WITH BACTERIAL EXTRACTS 



ON account of the rather high anticomplementary strength of 

 the insoluble portion of bacterial bodies themselves, in practical 

 complement fixation tests the effort is made to obtain the anti- 

 genie substance of the microorganisms in more or less pure solu- 

 tion. This is partially accomplished by extracting with distilled 

 water, by mechanical breaking up of the bacterial bodies, etc. 

 Bacterial complement fixation with antigens of this type is of 

 practical diagnostic use in gonorrhea, glanders, typhoid fever, 

 whooping cough and other diseases. 



Cultures of the same species of organism isolated from differ- 

 ent sources often show considerable biological differences, and 

 an immune serum which fixes complement with one such strain 

 often gives only partial fixation with another. For this reason, 

 in diagnostic tests, polyvalent antigens are used, i.e., antigens 

 made of numerous different strains of the bacteria in question. 



On account of the prolonged manipulations required students 

 will not make bacterial antigens for these tests, 1 but will be pro- 



1 The technique of preparing the Gonococcus antigen as practiced at the 

 New York Board of Health and supplied to us by the kindness of Miss M. P. 

 Olmstead is as follows : 



The strains used in the polyvalent antigen are ten of those shown by Torrey 

 to be serologically distinct A, B, C, G, K, L, N, O, Q, S. 



Stock transplants are kept on glucose ascitic agar, prepared as follows : 

 Bob veal, lean, chopped fine 1 Ib. 



Distilled H 2 O 1 liter. 



Mix, stand overnight at room tentperature. Heat to 45 C. one hour. 



