Protein analysis of CD14, BAX, and IGF1R in normal and ET platelets. (A) Intracellular CD14 expression was slightly increased in ET platelets (solid line) relative to normal platelets (dotted line), as shown by shifting of the curves to the right; staining was performed with anti-CD14 MoAb directly conjugated to phycoerythrin. (B) Intracellular CD14 expression was also slightly raised in the MK1 megakaryoblastic cell line (black area) relative to the isotype-matched MoAb-treated negative control (white area). (C) Intracellular BAX expression was markedly reduced in ET platelets (solid line) relative to their normal counterparts (dotted line). The cells were stained with BAX antibody followed by a fluorescein-conjugated goat anti–mouse immunoglobulin. (D) Membrane IGF1R expression was increased in ET platelets (solid line) relative to their normal counterparts (dotted line). Cells were labeled with IGF1R antibody followed by a phycoerythrin-conjugated goat anti–mouse immunoglobulin. The x-axis represents the relative fluorescence intensity; the y-axis, the relative number of cells. Results of 1 representative experiment (from 5 separate experiments) are shown for each protein.