Platelets develop new cell bodies in whole blood and express critical biomarkers. (A) Platelets were isolated from freshly collected (Baseline) or cultured (6 hours) whole blood as described in “Platelet isolation and culture.” The red and green stains identify sialic acids (WGA) and β-tubulin, respectively. (B) Freshly isolated platelets were cultured (6 hours) alone or in the presence (far right panels) of thrombin (0.01 U/mL). From left to right in the top row, the red stain identifies α_IIbβ₃, P-selectin, β-tubulin, control IgG, respiring mitochondria (Mitotracker), or sialic acids. Corresponding transmission images are shown in the bottom row. Scale bars represent 5 μm. Panels A and B are representative of 3 independent experiments.