Thrombus formation measured by surface area coverage or thrombus volume is linear in time. (A) Phase-contrast video images captured during the flow of PPACK-anticoagulated whole blood over collagen at 1000 s–1 were analyzed for platelet surface area coverage, which was plotted against perfusion time. Linear regression showed R2 = 0.97-0.99 (n = 3). (B) Thrombus volume was measured using blood supplemented with 30% of calcein-labeled autologous platelets. Z-stacks of x-y scans were measured in real-time by 2-photon laser scanning microscopy. Fluorescence image stacks were reconstructed 3 dimensionally and analyzed. Plots of thrombus volume compared with time were linear up to 300 s (R2 = 0.99). Representative plots are shown in panels A and B.
