Fragility of Erythrocytes 



291 



face of red blood cells in concentration insufficient to cause hemo- 

 lysis greatly increases the time of hemolysis in a time-fragility 

 test. When saponin is adsorbed by erythrocytes in a non-hemo- 

 lytic concentration the time of hemolysis by hypotonic saline 

 solutions is decreased. This increased and decreased fragility 

 demonstrates the presence of the hemolytic agent definitely in 

 connection with the red blood cell surface, and bears further 

 evidence that hemolysis by agents of this type is an adsorption 

 phenomenon. The difference of castor oil soap and saponin in 

 producing a decrease and increase in fragility would seem to 

 indicate that there is a difference of mechanism of hemolysis 

 even in those hemolytic agents acting by surface adsorption. 

 We have found a great difference of susceptibility to the action 

 of soap and saponin in the case of human, sheep and bovine 

 erythrocytes, and a similar variation is also observed in our 

 time-fragility tests. 



142 (2102) 



The fragility of erythrocytes in obstructive jaundice and 

 pernicious anemia. 



By ROBERT G. GREEN (by invitation). 



[From the Department of Bacteriology, University of Minnesota, 

 Minneapolis, Minnesota.] 



Our previous work demonstrating the action of small amounts 

 of hemolytic substances as castor oil soap and saponin in de- 

 creasing and increasing the fragility of red blood cells would 

 seem to have some bearing upon the fragility test as used in 

 medical diagnosis. The preliminary work to determine the role 

 of adsorption hemolysis in clinical conditions is here reported. 



Bile from various animals has been used as a hemolytic 

 agent for various animal erythrocytes and we have found 

 its action to be very variable in different samples. The 

 surface tension of bile solutions has also been studied and its 

 surface tension reducing property is likewise very variable. 



