Short in vivo life time of ARC1779. WT PRP was refrigerated with 10 μg/ml ARC1779 for 48 hours, and then transfused into WT recipient mice. At 0 min (considered as before transfusion), 20 min, 1, 2, 4, 8 and 24 hours after transfusion, 50 μl of whole blood was collected and plasma was isolated. An ELISA assay was performed to detect 1 μg/ml botrocetin-induced VWF-GPIb association, which can indicate the inhibiting activity of ARC1779. The OD at 450 nm of plasma collected at 0 min was normalized as 100% of endogenous VWF activity, meaning the inhibiting effect of ARC1779 at this time point was 0%. The values at 20 min, 1, 2, 4, 8 and 24 hours were compared to that at 0 min. Statistical analysis was performed by repeated measures ANOVA. Data are presented as mean±SD (n=3). n.s., not significant; **, P < 0.01.