SERUM DIAGNOSIS 46& 



ceptor, (3) complement, (4) antigen (bacterial extract), (5)^ 

 serum from the blood of the suspected animal to be tested. 



1. Red blood cells. The washed red blood corpuscles of 

 a sheep are obtained by bleeding a vigorous sheep from the 

 jugular vein under antiseptic precautions. The blood is 

 preferably collected in a sterile flask containing a few glass 

 beads. The blood is shaken, defibrinated and filtered through 

 sterile gauze into a glass tube. The tube is then filled with *' 

 physiological salt solution and the mixture centrifuged. The 

 supernatant fluid is poured off and the process repeated until 

 all the serum is removed from the corpuscles. Enough salt 

 solution is added to the sedimented corpuscles to make the 

 volume of blood equal the original amount filtered into the 

 tube. 



2. Hemolytic amboceptor. The hemolytic amboceptor 

 is obtained from the serum of a rabbit which has been im- 

 munized to the washed red blood corpuscles of a sheep. A 

 strong vigorous rabbit is selected and injected with the washed 

 red corpuscles. The injections are preferably made intra- 

 peritoneally and at intervals of 4-5 days. Two cc., 4 cc., 8 cc., 

 and 12 cc. of the corpuscles are respectively used for each in- 

 jection. In seven or eight days after the last injection a small 

 amount of blood is taken from the rabbit (by bleeding from 

 an ear vein) and the serum titrated to determine whether its 

 hemolytic action is sufficient ; that is, whether it will readily 

 dissolve the hemoglobin from the corpuscles of a sheep. If it 

 is found satisfactory the animal is bled from the carotid and 

 the serum collected and stored in small bottles. It is prefer- 

 able not to put more than 2 cc. in each bottle. The serum may 

 be preserved by adding 0.5 per cent of carbolic acid in a 5 

 per cent dilution. If the carbolized serum is not used for three 

 days after adding the carbolic acid it will not require inacti- 

 vation (heating at 56 C. for y 2 hour). Noguchi prefers 

 adding 2 drops of chloroform to each 2 cc. of hemolytic serum 



* For hemolytic work 0.85 per cent (Ehrlich) to 0.9 per cent 

 (Madsen) salt solution is universally employed. We prefer the lat- 

 ter concentration. 



