Collagen-coated glass slides were perfused with native human blood, and the deposited thrombi were double immunostained for TF and CD15.

(A) Electronmicroscopy showing platelets and PMN leukocytes within a thrombus. Note the PMN leukocyte–derived membrane attached to the platelet surface depicted in the boxed field. (B) Closeup examination of the boxed field: the structure double stains for CD15 (10-nm gold grains) and TF (5-nm gold grains). (C) TF on small particle-like structures in proximity to PMN leukocytes.