Anti-ADAMTS13 IgGs in murine plasma. Murine plasmas (1:10) obtained from wild-type mice (WT1-WT4), Adamts13^−/− mice transplanted with HPCs expressing GFP alone (O1-O4 and R1-R3) and GFP-ADAMTS13 (N1-N3 and P1-P4) at 3 months were incubated with immobilized purified murine ADAMTS13 on a microtiter plate. The bound IgG was detected by HRP-conjugated anti–mouse IgG as described in “Assay for murine plasma anti-ADAMTS13 IgG.” The positive control was serum (1:10 000 to 80 000) from a rabbit immunized with purified murine and human ADAMTS13 proteins (Anti-mAD13) according to the standard protocol. Negative control was negative in the wells with no ADAMTS13 immobilized despite of an incubation with rabbit anti-mAD13 serum (1:10 000) or murine plasma (1:10).