404 HEMOLYSINS 



A series of small test-tubes (10 by 1 cm.) are marked appropriately 

 and placed in a rack. To each tube 3 c.c. of the various hypotonic salt 

 solutions and 0.05 c.c. of the red blood-corpuscles (about 1 drop) are 

 added. The salt solution and corpuscles in each tube are well mixed, 

 and the whole series is placed in the refrigerator for from eighteen to 

 twenty-four hours, after which the readings are made. 



The tube of lowest dilution even if it shows but a trace of hemol- 

 ysis represents the point of initial hemolysis or minimal resistance. 

 The strength of salt solution in which all the corpuscles are hemolyzed 

 represents the point of complete hemolysis or maximal resistance. 



Normally, the minimal resistance is about 0.47, and the maximal 

 resistance about 0.3 (Morris). Hill 1 has found the points 0.457 and 

 0.340 respectively, for normal blood. 



1 Archiv. Inter. Med., 1915, 16, 809. 



