Localization of α-actinin 1 and NMMHCIIA in platelets. (A) Localization of α-actinin 1 and NMMHCIIA in resting platelets. Peripheral blood smears were stained with anti-α-actinin-1 antibody (Alexa Fluor 488, green) and anti-NMMHCIIA antibody (Alexa Fluor 555, red). Merged images are shown. There were abnormal NMMHCIIA aggregations in the neutrophils of patients with MYH9 disorders (indicated by arrow heads). M, mother; P, patient. Scale bar, 20 μm. (B) Localization of α-actinin 1 and NMMHCIIA in surface-activated spreading platelets. Surface-activated platelets were double-stained with anti-α-actinin-1 antibody (green) and anti-NMMHCIIA antibody (red). The fluorescence intensity of α-actinin-1 (green) and NMMHCIIA (red) along the lines of interest on the merged images was measured using the ImageJ plot profile function (National Institutes of Health, Bethesda, MD) and the data were exported to Microsoft Excel for the construction of graphs. Representative images from 10 spreading platelets in each individual are shown. The granulomere zone is indicated by dotted lines. Scale bar, 20 μm.