478 THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



suited with their gonococcus antigen; with serums from cases of cerebrospinal menin- 

 gitis (meningococcic) the results were negative. 



In the succeeding years numerous investigators, including Swinburne, Gradwohl, 

 O'Neil, Gardner and Clowes, Thomas and Ivy, Kolmer and Brown, have reported 

 favorably upon the practical value of the gonococcus complement-fixation test, 

 particularly as an aid in determining whether or not a patient is cured of the 

 infection. 



Technic. Since, because of the comparatively slight cellular in- 

 volvement, the quantity of antibody produced in a localized gonococcus 

 infection is probably small, the complement-fixation reactions are 

 generally weak, and consequently require the closest technical attention, 

 especially as regards the preparation of antigen and accurate adjust- 

 ment of the hemolytic system. 



Hemolytic System. As a rule, the antisheep hemolytic system is 

 employed; the various ingredients may be used in one-half the quantity 

 employed in the original Wassermann reaction, as given in the preceding 

 chapter, with the technic of the syphilis reaction, or one-tenth the quan- 

 tity employed in the original Wassermann technic may be employed. 

 I prefer to employ the larger amounts because the readings are usually 

 easier to interpret. 



Fresh guinea-pig complement .serum is diluted 1 : 20 and used in dose 

 of 1 c.c. ( = 0.05 c.c. serum); sheep's corpuscles are made up in a 2J^ per 

 cent, suspension and used in dose of 1 c.c.; antisheep amboceptor is 

 titrated (see p. 377) and used in an amount equal to !}/ hemolytic 

 doses in conducting the antigen titration and in the test proper. 



Kolmer and Brown have compared the practical value of the anti- 

 sheep and antihuman hemolytic systems in the examination of a number 

 of serums. When the latter were used, some of the reactions were 

 somewhat stronger and yielded slightly better results, showing the 

 influence, probably, of natural antisheep amboceptor present in a large 

 proportion of human serums. 



Antigen. This constitutes the most important ingredient of the 

 test. As Teague and Torrey and Schwartz and McNeal have em- 

 phasized, the antigen should be prepared of many different strains of 

 gonococci. The difficulty of isolating this organism and the constant 

 care required in subculturing and keeping a large number of strains alive 

 render it practically impossible for many persons to prepare a gonococcus 

 antigen. Therefore until simpler methods are devised, this antigen is 

 best prepared in large central laboratories, where the cultures are handled 

 and preserved by specially trained persons. 



The gonococci are well grown on a salt-free veal agar, neutral in 



