Drp1 is essential for mitochondrial organization in platelets. (A) Resting platelets were stained with mitoTracker (red) and then incubated for 30 minutes at RT with vehicle (control) or with the Drp1 inhibitor, Mdivi-1, at a final concentration of 50 μM. Platelets were then centrifuged onto the glass surface and placed into the incubator for 60 minutes at 37°C. Platelets were stained for tubulin (cyan) and shown are maximal projections of z-stacks. Scale bar, 2.5 μm (B) Resting and spread platelets of Drp1 WT and KO mice were incubated with the MitoView Fix 640, then either fixed immediately (resting) or centrifuged onto fibrinogen coated glass coverslips and incubated for 60 minutes at 37°C. Platelets were stained for actin (cyan) and shown are maximal projections of z-stacks. Scale bar, 2.5 μm