Figure 4: Transmission electron microscopy of platelets from ARPC1B-deficient patients and normal relatives.

Electron micrographs of fixed platelet sections taken at magnifications ranging from × 10,000 to × 40,000 (magnification on each panel; bars=500 nm, top left two panel bars=2 μm) indicate the presence of generally small and morphologically variable platelets in patient samples (see also Fig. 3). Dense granules were evaluated by whole mount transmission electron microscopy (Fig. 5b,c).