346 



BACTERIOLYSINS 



bacteriolysis in the exudate (Fig. 98). A smear of the culture stained 

 with dilute carbolfuchsin should also be on hand for making comparison 

 with smears of the exudate (Fig. 100). 



Bacteriolysis is first manifested by loss of motility. As the process 

 progresses many of the bacilli become swollen and distorted, and later 

 irregular and broken fragments or granules become apparent. Finally, 

 at the end of an hour, the exudate is practically sterile. In those cases 

 in which bacteriolysis is complete in an hour the animal generally sur- 





FIG. 96. REMOVING EXUDATE FROM THE PERITONEAL CAVITY OP A GUINEA-PIG 



(PFEIFFER BACTERIOLYTIC TEST) . 



A small incision is made through the skin, and the exudate is withdrawn by 



means of a pipet. 



vives. In the higher dilutions of serum bacteriolysis is incomplete, and 

 the animal becomes toxic and may succumb after twenty-four hours, 

 double the virulent dose being used in all injections. 



In the foregoing titration a serum that is bacteriolytic in dilutions 

 of 1 : 1000 or over will be satisfactory for purposes of diagnosis. When 

 preserved in a sterile condition in separate ampules in a dark cold place 

 the titer usually remains unaltered for several months. 



Dried Serum. If the serum is dried in vacuo, it will be necessary to 

 titrate with dilutions of the dried products in bouillon, as during the 



