Antibody and complement deposition is detectable on HOD × KEL RBC posttransfusion, with clearance of HOD × KEL RBC occurring in anti-KEL immunized recipients. (A) HOD × KEL RBC were labeled before transfusion into PBS (no antibody), anti-KEL–, or anti-HEL–treated WT mice. (B) IgG deposition was measured by direct antiglobulin test at 1, 2, and 24 hours posttransfusion. Total C3 (C) and active complement (C3b/iC3b) (D) was measured at 1, 2, and 24 hours posttransfusion. (E) RBC survival of HOD × KEL⁺ compared with HOD × KEL⁻ RBC at various times posttransfusion. Means ± standard deviation (SD) shown. (A-D) ****P < .0001, ***P < .001, **P < .01, and not significant (ns) by 1-way ANOVA with Tukey multiple comparison test. (E) ****P < .0001 and ns by 2-way ANOVA with Dunnett multiple comparisons test. Data shown include 5 mice per group and are representative of 3 independent experiments. DiI, 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate; DiO, 3,3′-dioctadecyloxacarbocyanine perchlorate; FSC, forward scatter; MFI, mean fluorescence intensity; SSC, side scatter.