Effect of MoAbs on LβIXV cell rolling. Before introduction into the parallel plate flow chamber, LβIXV cells were incubated with one of four MoAbs: SZ2 (anti-GP Ib), WM23 (anti-GP Ib), 5D2 (anti-vWF), or AK2 (anti-GP Ib). The mean velocity (A) was calculated on a digital image processing system using 1-second maximization images. The number of rolling cells (B) was determined by counting the total number of cells rolling on the vWF surface in a single field of view over a 4-minute flow period. During experimental runs, the entire system was maintained at 37°C. Dulbecco’s PBS was pumped through the chamber at a constant flow rate, producing a constant shear stress of 10 dyn/cm². Values are the mean ± SEM, n = 3.