Precipitin Reaction. 



203 



with normal serum indicated the presence of a non-specific factor 

 and raised the question as to whether the reactions occurring 

 with immune serum alone could be considered specific. 



Of 17 non-gonorrheal vaginal specimens from children 100 per 

 cent, reacted with immune serum and 94 per cent, with normal 

 serum. Nose and throat specimens and a miscellaneous group 

 of sputums, pus due to infection by bacteria other than gonococci 

 and peritoneal washings from normal mice or mice inoculated 

 with exudates due to pneumococcus or streptococcus, gave similar 

 non-specific reactions. 



Various methods have been employed in the attempt to elimi 

 nate or lessen the non-specific reactions, so that a specific reaction 

 could be recognized if it occurred. The standardization of the 

 opacity of " discharge extracts," the dilution of the serums or of 

 the extracts, or of both, and finally the heating of the extracts 

 have failed to be of help. 



With gonococcus serums, precipitates were most frequently 

 encountered with antigens prepared from the staphylococcus and 

 meningococcus. Absorption of gonococcus serums by these 

 heterologous types did not reduce appreciably the reactions ob- 

 tained with extracts from non-gonorrheal sources. 



That the reactions obtained with gonococcus case extracts 

 could not be considered as specific was most conclusively shown 

 by the persistence of reactions after the gonococcus serum was 

 absorbed by the gonococcus. That is, when gonococci were added 

 to the serum to the point where it no longer reacted with a known 

 gonococcus antigen, it still gave a precipitate with extracts from 

 gonococcus cases. Although a specific reaction might have oc- 

 curred at times, the presence of this non-specific factor would have 

 obscured it. 



The precipitin reaction, therefore, as recommended by Robin- 

 son and Meader is not applicable for the determination of the 

 presence of the gonococcus in discharges from the cervix, urethra, 

 etc. 



