Neutrophils effectively phagocytose activated platelets. Resting or activated platelets were incubated with neutrophils at a 20:1 ratio. At different times (x axis, minutes) cells were fixed and processed for electron microscopy. (A) For each sample, 40 to 50 neutrophils were randomly selected and analyzed for the presence of internalized platelets. Neutrophils with at least 1 platelet completely included in a phagosome were considered positive. Data are expressed as mean ± SD of the percentage of neutrophils with internalized platelets; n = 5. (B) Representative electron microscopy of neutrophils cultured alone. (C) Representative electron microscopy of neutrophils incubated with resting platelets. (D-H) Representative electron microscopy of neutrophils incubated with activated platelets.