486 THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



6. The corpuscle control, containing 1 c.c. of corpuscle suspension 

 and 3 c.c. of saline solution. This tube should be plugged with cotton. 



All tubes are gently shaken and incubated for an hour, after which 

 \Yz units of hemolytic amboceptor and 1 c.c. of corpuscle suspension are 

 added to all except the corpuscle control. The tubes are gently shaken 

 and reincubated for an hour or two, depending upon the hemolysis of 

 the controls. 



The controls are first inspected. They should all show complete 

 hemolysis, except the first three tubes of the positive serum series and the 

 corpuscle control. Inhibition of hemolysis in the first three tubes of 

 the series containing the unknown serum indicates a strong positive 

 reaction. Complete hemolysis in all tubes indicates a negative reaction. 

 Partial hemolysis in the first three tubes indicates a partially positive 

 reaction. If the serum control or antigen control tubes should show in- 

 hibition of hemolysis, these were probably anticomplementary and the 

 test should be repeated. 



COMPLEMENT-FIXATION TEST IN CONTAGIOUS ABORTION 



It is now generally conceded among veterinarians that the Bacillus 

 abortus of Bang is the specific cause of contagious abortion of cows. 



Evidence is gradually accumulating to show that an organism be- 

 longing to the paratyphoid group is frequently the cause of a similar 

 condition among mares (Kilbourne and Smith, 1 Liguierer, 2 Liguierer 

 andZabala; Good; 3 VanNeelsbergen; 4 deJong; 5 Meyer and Boerner) 6 . 

 Meyer and Boerner, who have studied this bacillus with particular care, 

 classify it with the paratyphoid-enteritidis group (Bacillus aborti equi). 



Veterinarians are generally agreed that in contagious abortion of 

 cows the complement-fixation test is highly specific, and is frequently of 

 considerable value in establishing a diagnosis (Meyer and Hardenburgh 

 and others). 



Meyer and Boerner have found fixation of complement to occur in 

 contagious abortion of mares with an antigen of Bacillus abortus equi, 

 and recommend the test as diagnostic aid in this infection. 



1 Kilbourne and Smith: United States Department of Agriculture, Bulletin No. 

 3, 1893, 49 and 53. 



2 Liguierer: Rec. Med. veterinaire, Ixxxii, 1905. 



3 Good: Kentucky Agriculture Exper. Station Bulletin No. 165, 1912 



4 Van Neelsbergen: Tijdschrift. v. Veeartsenijk., xxiv, 1912. 



5 de Jong: Archiv. f. Wissenshaftl. u. prak. Tierheilkunde, xxv, 1900. 



6 Meyer and Boerner: Jour. Med. Research, 1913, xxix, No. 2, 325. 



