SERUM DIAGNOSIS 477 



After the required incubation period the tubes are re- 

 moved from the incubator and to each tube is added 1 cc. of 

 the previously titrated rabbit serum (hemolytic amboceptor). 

 This serum has previously been inactivated by heating to 

 56-57 C. for one-half hour, provided it has not been carbol- 

 ized and kept for three days. Finally 1 cc. of a 5% suspension 

 of the washed red corpuscles of a sheep is added to each tube. 

 The tubes are now replaced in the incubator and left for 10 

 hours, when the results may be read. If put in a water bath at 

 37 C. and left for 1 hour and then removed and kept at room 

 temperature for from 3-5 hours the results may be read. Some 

 workers prefer reading the results as soon as removed from 

 the water bath. If the horse was affected with glanders, that 

 is, the serum of the animal contained bacteriolytic ambocep- 

 tor, no hemolysis will have taken place in tubes 1 and 3. The 

 red corpuscles will have settled to the bottom and the upper 

 liquid will be clear. The controls Nos. 2 and 4 should show 

 complete hemolysis, that is, the fluid in the tubes should be 

 uniformly red. If, however, the suspected serum came from 

 a healthy horse and did not contain the bacteriolytic ambo- 

 ceptor, hemolysis should take place in tubes Nos. 1 and 2. 

 Mohler gives the following advice in the interpretation of the 

 results of the test. 



1. "Horses in which the serum produces a complete fixa- 

 tion of the complement in the quantities of 0.1 cc. and 0.2 cc. 

 should be considered as glandered. 



2. "Horses in which the serum gives a complete fixation 

 in the quantity of 0.2 cc. and an incomplete fixation in the 

 quantity of 0.1 cc. should likewise be considered glandered. 



3. "Horses in which the serum produces an incomplete 

 fixation of the complement in the quantities of 0.1 cc. and 

 0.2 cc. should also be considered as glandered. 



4. "Horses in which the serum shows no fixation of the 

 complement in either tube should be considered free of glan- 

 ders." 



In order to reduce the possibility of error to a minimum 

 the agglutination test may be applied to the latter cases, and 



