712 
Journal of Agricultural Research voi. xxvn, No. 9 
a large quantity of cold saline and again thrown down in the centrifuge. 
After removing the supernatant fluid the sediment was resuspended in 
4 cc. of saline. 
TREATMENT OF SUPERNATANT FLUID 
The supernatant fluid containing the complement represented a dilution 
of one in four. Gradually increasing quantities of this dilution were 
placed in a series of five tubes and to this was added one unit of anti¬ 
sheep hemolysin (rabbit) and 0.5 cc. of a 5 per cent suspension of 
sheep cells. Saline was added to make the total volume in each tube 
equal to 2 cc. A control tube was added which contained 0.5 cc. of 
diluted complement and sheep cells, to determine the presence of ambo- 
cepter. Table I gives the amount of each reagent used. 
Table I. —Titration of complement in chicken serum 
Tube No. 
1 
a 
3 
4 
5 
! 6 
: 
% 
Supernatant fluid (complement). 
0. 2 
O.4 
0. 6 
0.8 
1. 0 
! 0.5 
Amboceptor (1 unit). 
. 1 
. I 
• 1 ! 
. 1 
. 1 1 
• 0 
Cells (5 per cent). 
• 5 
• 5 
• 5 i 
• 5 ! 
! • 5 | 
• 5 
Saline. 
1. 2 
1. 0 
.8 
1 
1 .6 j 
: - 4 | 
1 1.0 
All tubes were incubated at 37 0 C. for one hour and placed in the ice 
box over night. The results are recorded in Table II. 
Table II. —The action of supernatant fluid (1 complement) and one unit of antisheep 
amboceptor ( rabbit ) on sheep cells 
One unit of antisheep amboceptor (rabbit) and 0.5 
cent sheep cells plus supernatant fluid. 
cc. of 5 per 
0.5 per cent 
of sheep cells 
plus supei - 
natant fluid. 
Supernatant fluid.. 
0. 2 
i 
0.4 
0. 6 
0. 8 
I. 0 
o-S 
Bird No. 
i 
f 
1 
a 0 
0 
0 
0 
<* + 
0 
0 
0 
0 
0 
O 
0 
3 . 
0 
0 
0 
+ 
O 
0 
0 
«+ + 
+ + 
+ + 
+ + 
0 
5 . 
0 
+ 
+ 
+ 
+ + 
0 
6. 
0 
0 
0 
0 
O 
0 
7 . 
0 
0 
0 
0 
O 
0 
8. 
0 
+ 
+ + 
+ + 
0 
9 . 
0 
0 
0 
+ 
+ 
0 
10. 
0 
0 
+ 
+ 
O 
; 0 
11. 
0 
0 
0 
+ 
O 
O 
12. 
1 
+ 
+ 
+ + 
+ + + 
M-+++ 
° 
*3 . 
0 
0 
0 
0 
0 
! 0 
14. 
0 
' 0 
0 
0 
+ 
0 
15. 
0 
+ 
+ 
+ + 
4 - 4 - . 
I ° 
16. 
0 
+ 
+ + 1 
++ 
+ 4 - 4 - 
0 
17. 
0 
0 
0 
+ 
0 
18. 
0 
0 
0! 
0 
0 
j 0 
19. 
0 
0 
0 1 
0 
0 
0 
20. 
0 
0 
° 
0 
0 
0 
21. 
0 
0 
0 ! 
0 
0 
0 
22. 
0 
0 
0 
i 
0 
! 
0 
0 
++ + + = complete; +++=marked; -f+=partial; +=trace; o=*no hemolysis. 
