Treatment of anti-D with EndoS does not affect the binding of anti-D to RBCs. (A) Western blot analysis of anti-D on RBCs using peroxidase-conjugated anti–human IgG. (B) Glycan hydrolysis of anti-D on RBCs determined by lectin ELISA (optical density [OD] = 450 nm). (C) Quantification of RBC-bound anti-D by ELISA (OD = 450 nm) using antiserum against human IgG.