A simple and accurate microfragility test for measuring erythrocyte resistance

Abstract

Abstract A new microfragility test, utilizing the same principle as that originally employed by Hamburger and used for clinical purposes by von Limbeck and by Ribierre, and later modified by numerous workers, particularly Giffin and Sanford, but greatly simplified and especially adapted for use in small infants and animals, is described. As tested by this method, initial hemolysis of normal human erythrocytes is found to occur at an average of 0.420 to 0.435 per cent concentration of sodium chloride solution, while complete hemolysis is most frequently seen at 0.315 to 0.330 per cent concentration. The normal range or span of hemolysis is thus approximately 0.1 per cent concentration. The simplicity and accuracy of the test are the features especially adapted to routine hematologic examination. A few illustrative examples of the results obtained by this method in various diseases characterized by abnormalities in erythrocyte fragility are reported. The striking increase in erythrocyte fragility in a case of erythroblastosis fetalis (icterus gravis neonatorum), as revealed by the microfragility test, suggests the fundamental mechanism in the causation of icterus in the newborn. The normal hemolysis ranges of erythrocytes in a few mammals and pigeons, as measured by the microfragility test, are also recorded in this preliminary report.