Comparison of experimentally measured and theoretically calculated ODCs and sickling vs pressure curves. (A) ODC. The ODC (thick continuous blue curve) measured with a Hemox Analyzer is the average curve determined for blood from 7 patients with SCD, with a mean Hb composition of 83% HbS, 14% HbF, and 3%HbA2. The insets show the average intracellular Hb concentration distribution (black points) measured for the 7 samples. The thin blue curves show the standard deviation from the mean resulting from patient-to-patient variation. The thick continuous red curve ODC is the theoretically calculated average curve for blood from the 7 patients with the standard deviation from the average indicated by the thin red curves. The inset shows the average intracellular Hb concentration (black points) measured in the 7 samples. (B) Sickling. The blue points are the average measured fraction sickled vs time in 23 patients with SCD, with the sum of the HbF and HbA2 percentages less than 12%; the mean hemoglobin composition is 92% HbS, 4% HbF, and 4% HbA2, with error bars representing the standard deviation from the average resulting from patient-to-patient variation.