Lineation of the osmotic fragility curve of erythrocytes

Lineation of the osmotic fragility curve by the method of Detraglia et al (1974) may be performed in most samples from a hospital population. Using the lineation procedure, the osmotic fragility may be tested by only 2 solutions of known osmolarity without any great loss of precision or accuracy. The osmotic fragility curve may be described by 2 values: C50 = the concentration at which 50% of the erythrocytes are haemolyzed and C50--C80 = the decrease in concentration raising the fraction of haemolysis from 0.50 to 0.80.