WASSERMANN AND OTHER COMPLEMENT FIXATION TESTS 



229 



contents and the tube is then inverted and shaken a sufficient number of times 

 to evenly distribute the cells throughout the fluid; the tubes are again centrifu- 

 galized until all the .cells settle to the bottom; the salt solution is pipetted off. 

 This washing is repeated twice. After the third washing the cells are ready to 

 be injected into the rabbit. 



Only large healthy rabbits should be used. With a pair of scissors the hair 

 is removed so as to expose one of the veins on the margin of the ear. Half a 



FIG. 37. 



A, Citrated blood as poured into centrifuge tube. B, Cells precipitated to the bottom 

 of the tube, clear serum and citrate solution above. Result of centrifugalizing A. C, Removal 

 of supernatant fluid. D, Test tube containing red cells after supernatant fluid has been removed. 



cubic centimeter of red blood cells is poured into a small (2 cc. capacity) Luer 

 syringe, and with the finest needle through which the cells will pass, they are 

 injected into the vein (Fig. 39). 



Twenty-four hours after the first injection, in exactly the same manner, the 

 second is given, the quantity of red blood cells injected being i cc. 



Twenty-four hours after the second injection a third is given quantity 2 cc. 



Twenty-four hours after the third injection the last one is given quantity 

 3 cc. 



