Whole blood treated with aWr^b scFv shows increased platelet adhesion in response to flow over TNF-α–activated endothelium compared with blood treated with aRh17. (A) Representative image of endothelialized channels subjected to flow with either (top) aWr^b scFv treated whole blood or (bottom) aRh17 scFv treated whole blood. Blood was collected in citrate with corn trypsin inhibitor, incubated with scFv (500 nM) for 15 minutes, recalcified, and flowed over channels for 15 minutes after which images were captured across the channels. Prior to flow, platelets and leukocytes were stained by addition of calcein AM dye. (B) Quantification of the experiments in panel A (mean fluorescence intensity) demonstrates a significant increase in calcein AM signal in the aWr^b scFv–treated blood but not aRh17 scFv (n = 4, *P < .05, 1-way ANOVA).