Correlation of platelet counts to platelet adhesion on collagen. Platelet-reduced blood was prepared with PPACK-treated whole blood. Platelet-reduced blood having the appropriate platelet counts was prepared by mixing the erythrocyte fraction and diluted PRP with PPP. The mepacrine-labeled blood was perfused in the flow chamber for 2 minutes at a shear rate of 1600 s^–1. (A) Relationship between platelet counts and platelet adhesion. Platelet adhesion was expressed as surface coverage at 2 minutes after the start of flow. Data are each a mean of duplicate measurement values. (B) Photo images of the platelet adhesion under normal and platelet-reduced conditions. Photo images were captured at 2 minutes after starting the perfusion using the reconstituted blood of 19 × 10⁴ or 4 × 10⁴ platelets/μL. Magnification, × 400.