Red blood cell-plasminogen activator (RBC-PA), but not free PA, incorporated into clots provides reperfusion in a flow system. (A) Fibrinolysis monitored by quantitative confocal microscopy triggered by free PA (0.0344 μM, final conc) + 2% hRBCs, 2% RBC-PA (equivalent to 0.136 μM uPA), or non-lysing control + 2% hRBCs in a static model system. (B) Permeability constant for liquid perfusion in the flow system for the same samples as (A). (C) Permeability for cellular components, represented as the number per μL of buffer-derived RBCs that permeated the clot during lysis. Plots are representative of six (A, B) and three (C) independent experiments.