HDAC6 inhibition alters the structure of the platelet marginal band. A: purified human platelets were pretreated with TSA (10 μM), tubacin (10 μM), or vehicle alone before stimulation with 1 μg/ml CRP. After 5 min, platelets were fixed, immobilized on coverglass, stained with antibodies directed against α-tubulin, and examined by SR-SIM. Representative 0.56-μm slices from three separate experiments are shown. Wide field scale bar, 10 μm. Zoomed image scale bar, 1 μm. B–D: after fixation, platelets were also examined by DIC microscopy (B and C) and quantitative volumetric analysis (D) as described in materials and methods. Central box marks indicate median values of platelet volume; box edges represent 25th and 75th percentile values. Whiskers extend to the most extreme nonoutlier data points. *Values significantly lower than that of resting platelets (basal).