Rh null iRBCs have comparable O2 binding capacity and deformability compared with WT iRBCs. (A) Representative and (B) quantification of alpha-like and beta-like globin chain analysis of day 12 iRBCs by HPLC (n = 5 independent assays). (C) Representative and (D) quantification of hemoglobin tetramer analysis of day 12 iRBCs by HPLC. (n = 5). (E) O2 dissociation curve of adult dRBCs, PB-RBCs, WT and Rh null iRBCs. (F) The partial pressure of O2 at 50% oxyhemoglobin (p50) interpolated from Sigmoidal 4PL curves of each type of RBC (n = 3 each, one-way ANOVA), ∗P < .05; ∗∗P < .01. (G) Average elongation indices of dRBCs, PB-RBCs, and WT or Rh null iRBCs determined by Lineweaver-Burk fitting for ektacytometry (n = 6 dRBCs, n = 3 for all others). (H) Elongation indices at 5 Pa, 10 Pa, and maximum elongation (n = 6 dRBCs, n = 3 for all others, two-way ANOVA), ∗∗∗∗P < .0001. (I) Representative images of fully “stretched” dRBCs, pbRBCs, and iRBCs obtained on the RheoScan AnD system. ANOVA, analysis of variance; HbF, fetal hemoglobin; O2, oxygen; Pa, Pascal; PB-RBCs, peripheral blood CD34+ cultured RBCs; WT, wild type.
