THE MANUFACTURE OF ANTISERUMS 585 



involves the injection of a small dose of mallein under the skin of the 

 eyelid. ■ 



The stock culture of the glanders organism used in the preparation 

 of mallein should be one which possesses known virulent properties. 

 It is grown at a temperature of 37° for several weeks in flasks of glycerin 

 bouillon* having a chemical reaction of about three points acid to 

 phenolphthalein. When the cultures are removed from the incubator 

 they are heated in streaming steam, passed through a Berkef eld filter 

 and the filtrate is concentrated, preserved and distributed in labeled 

 vials. ^ 



Suspensions for the Agglutination Tests 



Agglutinin's are hypothetical bodies existing in the blood and possi- 

 bly other body tissues, of an individual affected with, or convales- 

 cent from, a specific infectious disease. The bodies possess the power 

 of "clumping" and precipitating the specific bacteria which are the 

 cause of the disease in question. Thus, if a dilution of blood serum from 

 a typhoid fever patient is mixed with living typhoid organisms, the 

 specific agglutinins present in the serum will cause thft organisms to 

 cease their motion and agglutinate or clump together in irregular 

 masses. Normal human blood serum placed under the same conditions 

 will fail to cause the agglutination of the organisms in similar dilutions. 

 The agglutination reaction may, therefore, be used in the diagnosis of 

 certain specific infectious diseases. The serum must be properly 

 diluted in order that the reaction may be of diagnostic value, because 

 undiluted, normal serum will cause a positive agglutination reaction 

 in most cases. 



The agglutination test is used as a practical aid chiefly in typhoid 

 fever in man and glanders in horses. The test may be conducted either 

 microscopically or macroscopically. In the microscopic method, the 

 diluted serum from the suspected case is placed under the microscope 

 with the live, specific organisms in hanging drop. In the macroscopic > 

 method, the serum is added to an emulsion of the killed (heated) 

 bacteria in small test-tubes, and the residting reaction detected with the 

 naked eye. 



The emulsion, suspension or "test fluid" for the typhoid agglutina- 

 tion test is prepared from a pure culture of B. typhosus. The organism 

 is grown for twenty-four hours upon agar at a. temperature of 37°. 



