Frequency distribution of spontaneous storage or stress-induced hemolysis by donor racial background. RBC concentrates from RBC-Omics donors 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.” The plots represent the frequency distribution of percentage of storage or stress-induced hemolysis in donors of different racial backgrounds including non-Hispanic white, Hispanic white, non-Hispanic African American, and non-Hispanic Asian. For simplification, hemolysis data from other donors were excluded from this figure and can be viewed in Table 3. (A) Percent osmotic hemolysis (4-hour Pink test). (B) Percent AAPH-induced oxidative hemolysis (incubation conditions: 150 mmol/L, 1.5 hours, 37°C). (C) Percent storage hemolysis at the range of 0% to 1% (acceptable for transfusion) and (D) above 1%.