The binding of rhCD59-P to mouse erythrocytes following in vivo administration. CD1 mice (3 per group) were injected with either vehicle or rhCD59-P (10 mg/kg). Blood samples were removed from tail bleeds at time intervals, and surface levels of human CD59 were determined by flow cytometry using a fluorescent anti–human CD59 antibody. Histograms show data from the treated group following 1 hour (A), 4 hours (B), 24 hours (C), and 48 hours (D). The mean fluorescent intensities from each group are summarized in panel E.