G6B is expressed on the surface of platelets. Relative expression of the G6B splice forms G6B-A (A), G6B-B (B), G6B-D (C), and G6B-E (D) in a range of cell types. In each panel, expression is shown relative to the cell type with the lowest ΔCT value.⁵  In each case, the dashed line shows the median value; and the solid black line, 2 standard deviations above the median value. Data are representative of 3 individual experiments. (E) Western-blot analysis of G6B expression in whole buffy coat (lane 1), CD4⁺ T cells (lane 2), CD8⁺ T cells (lane 3), CD14⁺ monocytes (lane 4), CD16⁺ granulocytes (lane 5), CD19⁺ B cells (lane 6), and platelet-rich plasma (lane 7). Due to the size differential between nucleated blood cells and platelets and to ensure equivalent protein mass per lane, 100-fold more cells were loaded in lane 7 compared with lanes 1 to 6. Gel was visualized with a G6B mAb and detected with a goat anti–mouse HRP conjugate as described in “Materials and methods.” Size standards are indicated to the right of the gel. (F-G) Flow cytometry of platelets showing surface expression using affinity-purified G6B mAb (solid line), isotype control (dotted line), and platelets alone (dashed line). Panel F shows expression on washed resting platelets gated on the CD41⁺ population and panel G shows ADP-activated platelets gated on the CD62-P⁺ population. Region A represents the number of positive cells above unstained platelets.