A deficiency of platelet-dense granules is the only obvious ultrastructural abnormality in C3H/HeSnJ ashen mice.

Normal C3H/HeSnJ platelets (above) and mutant C3H/HeSnJ ash/ashplatelets (below) were examined by electron microscopy. The platelet pellets were osmicated and stained with 190 tannic acid in 0.05 M sodium cacodylate. Electron microscopy grids were then stained with lead citrate. Arrows indicate the typical “bulls eye” appearance of dense granules in normal platelets. Bar is 1 μm.