Platelets from THC2 patients have reduced azurophilic granule content. Platelets in peripheral blood smears (May-Grünwald-Giemsa staining) from 4 different probands were normal in size and appeared pale because of reduced content (B,D) or complete absence (A,C) of azurophilic granules. (A) One platelet had a normal granule content. Scale bars represent 10 μm. Images were acquired by an Axioscope 2 Plus microscope (Carl Zeiss) using a 100×/1.30 (oil-immersion) Plan Neofluar objective (Carl Zeiss). The Axiocam MRc5 camera (Carl Zeiss) and Axiovision 4.6 software (Carl Zeiss) were used to capture and process images.