Credit: Journal of Clinical Investigation; Adapted from Figure 8-H, "Platelet-Derived Myeloid Related Protein-14 (S100A9) Regulates Thrombosis"
The blood clot, or thrombus, was extracted from a heart attack patient's cardiac artery and stained for MRP-14 and platelets. This slide image shows that platelets are loaded with MRP-14, and those appear as yellow areas.