Platelet CFH is distributed throughout the cell and not preferentially localized to α-granules. Thin-section TEMs of representative normal platelets immunogold labeled for CFH (original magnification ×40 000). White bar represents 500 nm; white arrows, α-granules. Primary anti-CFH rabbit polyclonal antibody was detected by immunogold-tagged (10 nm) secondary antibody (black spots). Immunogold-CFH was distributed throughout the cytoplasm with some on the surface but none in recognizable α-granules (compare white arrows with black spots).