Distribution of spontaneous storage or stress-induced hemolysis by donor age and sex. RBC concentrates from male or female donors age 18 to 90 years old were stored (1-6°C) for 39 to 42 days in transfer bags and tested for storage or stress-induced hemolysis as described in “Materials and methods.” (A) Percent spontaneous storage hemolysis. (B) Percent osmotic hemolysis (4-hour Pink test). (C) Percent AAPH-induced oxidative hemolysis (incubation conditions: 150 mmol/L, 1.5 hours, 37°C). The fitted line indicates the predicted mean hemolysis for corresponding age, and the shaded areas highlight the 95% confidence intervals for the standard error of the mean.