XI. B, 1 Ruediger: Hxmolysis by Human Serum 43 



end of three hours the second tube was centrifuged, and the 

 serum was pipetted off and tested for hsemolytic power. It still 

 dissolved the horse corpuscles. After five hours the third and 

 fourth tubes were centrifuged, and the serum was pipetted off 

 and tested for hsemolysin. Of this serum 0.4 cubic centimeter 

 still produced a trace of haemolysis with one half of the usual 

 test dose of horse corpuscles, but 0.2 cubic centimeter of serum 

 mixed with half the usual dose of corpuscles failed to produced 

 haemolysis. 



Now an attempt was made to reactivate the heated human 

 serum (portion B) with human complement (portion C) and 

 with guinea pig complement freed from antihorse amboceptor. 



Technique. — Three sets of test tubes were prepared. Each 

 set contained three tubes designated as 1, 2, and 3. The first 

 set received unheated human serum (portion A) ; tube 1 re- 

 ceived 0.4 cubic centimeter of serum; tube 2 received 0.2 cubic 

 centimeter of serum, and tube 3 received 0.1 cubic centimeter 

 of serum. Each tube received 0.5 cubic centimeter of 4 per cent 

 suspension of horse corpuscles and enough physiologic salt solu- 

 tion to make the total quantity 2.5 cubic centimeters. In set 

 2 the heated human serum was reactivated with human comple- 

 ment. Tube 1 received 0.4 cubic centimeter of complement se- 

 rum, 0.5 cubic centimeter of 4 per cent suspension of horse 

 corpuscles, and enough physiologic salt solution to make the 

 total quantity 2.5 cubic centimeters. Tube 2 received 0.2 cubic 

 centimeter of heated serum, 0.2 cubic centimeter of complement 

 serum, 0.5 cubic centimeter of 4 per cent suspension of horse 

 corpuscles, and enough physiologic salt solution to make the 

 total quantity 2.5 cubic centimeters. Tube 3 received 0.1 cubic 

 centimeter of heated serum, 0.1 cubic centimeter of comple- 

 ment serum, 0.5 cubic centimeter of 4 per cent suspension of 

 horse corpuscles, and enough physiologic salt solution to make 

 the total quantity 2.5 cubic centimeters. 



In set 3 the heated serum was reactivated with guinea pig 

 serum freed from natural antihorse amboceptor. Tube 1 re- 

 ceived 0,4 cubic centimeter of heated serum and 0.4 cubic centi- 

 meter of complement serum. Tube 2 received 0.2 cubic centi- 

 meter of heated serum and 0.2 cubic centimeter of complement 

 serum. Tube 3 received 0.1 cubic centimeter of heated serum 

 and 0.1 cubic centimeter of complement serum. To each tube 

 was added 0.5 cubic centimeter of 4 per cent suspension of horse 

 corpuscles and enough physiologic salt solution to make 2.5 cubic 

 centimeters. 



