STEM tomography reveals that the canalicular system and α‐granules remain separate compartments during early secretion stages in blood platelets

Essentials•How platelets organize their α‐granule cargo and use their canalicular system remains controversial.•Past structural studies were limited due to small sampling volumes or decreased resolution.•Our analyses revealed homogeneous granules and a closed canalicular system that opened on activation.•Understanding how platelets alter their membranes during activation and secretion elucidates hemostasis.Summary: BackgroundPlatelets survey the...