THE WHOLE BLOOD TEST FOR PULLORUM DISEASE 9 



Table L-Variation in measurements of antigen. 

 Quantities of Antigen Number of Drops 



(cc. per drop) 



.042 2 



.043 4 



.044 17 



.045 19 



.046 10 



.047 16 

 .048 3 



.049 6 



.05 4 



.051 6 



.052 4 



.053 2 



.054 5 



.055 2 



100 



Whole Blood Measurements. The whole blood was measured with a wire loop 

 having a 6 mm. diameter. With the wire loop the blood was collected from the 

 wing vein puncture and measured with a graduated pipette. It was impossible 

 to obtain uniform loopfuls of blood from each bird, especially when the blood did 

 not escape freely or did not accumulate to such an extent that the loop would fill 

 and withdraw the proper amount of blood. Table 2 shows that greater variation 

 was found in 100 blood measurements than in the antigen measurements. While 

 the majority of the measurements ranged from .03 to .045 cc, the minimum and 

 maximum amounts were .022 and .05 cc, respectively, a range of .028 cc. The 

 average for the 100 measurements was .03541 cc. It is reasonable to suspect that 

 such a variation would influence the degree of agglutination reaction, especially 

 in low-titre birds. 



Table 2. --Variation in measurements of fresh whole blood. 



Quantities of Whole Blood Number of Loopfuls 

 (cc. per wire loop) 



.02 —.024 2 



.025— .029 7 



.03 —.034 28 



.035— .039 31 



.04 —.044 30 



.045— .05 2 



100 



Influence of Blood-Antigen Dilution on Degree of Agglutination. In this ex- 

 periment a number of positive-reacting birds were employed. The blood samples 

 were collected into tubes containing 10 percent sodium citrate solution in amounts 

 (1 part sodium citrate and 14 parts blood) to prohibit coagulation. The drop 

 method was used for measuring the antigen, while a graduated pipette was em- 

 ployed to measure the citrated whole blood. The amounts of blood tested were 



