ON H^MOLYTIC RECEPTORS 121 



immune-body are added to each tube, and then to the tubes in the 

 two series 0-075, 0-1, 0-125, 0-15, 0-175, 0-2 and 0-25 c.c. of comple- 

 ment. The tubes in both series give the same amount of complement 

 taken up, the tubes with 0-15 c.c. of complement giving a mere 

 trace of lysis of the added corpuscles. Therefore about 0-145 c.c. of 

 complement was taken up in each. M.H.D. of complement = 

 0-015 c.c. 



The receptors are accordingly not destroyed by lysis with 

 water. 



It is evident that various haemolytic agents might be tested 

 in the same way. The only other one which we have used 

 is ether. 



In this case a sufficient amount of ether to produce complete lysis 

 is added to the suspension of red corpuscles (say 2 c.c. of ether to 

 10 c.c. of suspension). After laking, the fluid is placed in the incu- 

 bator at 37 C. in order to evaporate off the ether. Two series of 

 tubes are prepared as before, each tube containing 1 c.c., in the 

 one case of the suspension, in the other of the red fluid resulting from 

 laking. 



Example. Two series of tubes, each containing 1 c.c. of suspen- 

 sion of red corpuscles in 0-85 per cent, sodium chloride solution, are 

 prepared. In one series laking is produced by ether and the ether 

 is evaporated off ; in the other series the corpuscles are left untreated. 

 6 doses of immune-body are then added to each of the tubes and 

 increasing amounts of complement, namely, 0-02, 0-05, 0-1, 0-15, 0-2, 

 0-25 c.c. of complement. 



The result is the same as in the case of laking with water, 

 the tube with 0-15 c.c. of complement giving a small trace 

 of complement over in both series, i. e. the receptors of the 

 laked corpuscles take up as much complement through the 

 medium of immune-body as the receptors of the untreated 

 corpuscles. 



Accordingly neither water nor ether in causing laking of 

 the corpuscles produces any change in the affinity of the 

 receptors for immune-body and, through this intermediary, 

 for complement. 



