go ALAN ARTHUR BOYDEX. 



after the preliminary titration. Both rabbits and fowls were 

 starved for eighteen hours preceding the final bleeding in order 

 that the blood be as clear as possible. 



The rabbits were bled from the dorsal aorta. The animals 

 were first anresthetized with ether and then a median ventral 

 incision was made. The viscera were moved to one side and the 

 dorsal aorta carefully cleaned of fat and connective tissue for a 

 short distance. The aorta was then clamped off centrally and 

 distally and a sterile canula inserted through a small incision 

 and securely ligatured. The central clamp was then removed 

 and the blood allowed to flow through sterile rubber tubing into 

 centrifuge tubes. In this manner 75-100 cc. of blood were 

 usually obtained. 



Fowls were bled completely after decapitation, the amount 

 of blood varying from 35-125 cc. depending upon the size of the 

 individual. 



The blood was allowed to stand for two or more hours in the 

 ice-box after which time the clot was broken up and the blood 

 centrifugalized. The antiserum was then poured off and stored 

 in 5 cc. sterile, rubber-stoppered vaccine vials which were then 

 kept in the ice-box. In many cases the antisera were filtered 

 through small Berkfeld filters before bottling to insure sterility. 



The blood sera used as antigens were obtained from healthy 

 animals. The beef and pig bloods were obtained from the 

 Mayer Packing Plant, the horse blood from Mr. Fred Rieder, 

 and the sheep and goat bloods from animals kept by the De- 

 partment of Zoology. Besides these, other bloods were used for 

 tilration only. The latter included human, rat, guinea pig, 

 rabbit, fish (carp) and fowl. The sera were obtained after 

 clotting and centrifugalizing and were usually filtered through 

 Berkfeld filters before storing in 5 cc. ampules in the ice-box. 



From these blood sera standard solutions were made. These 



standards were usually 2 or 4 per cent, dilutions of a given 



serum in normal saline (sometimes 10 per cent.). The standards 



wi-rt- made in 100 cc. volumetric flasks and filtered through a 



Berkfeld filter and then stored in the usual manner in 5 cc. 



The concentration of protein in each standard was de- 



<1 by making modified Kjeldahls on 5 or 10 cc. samples 



