Cell-surface expression of Ku80 in human bone marrow cells. Flow cytometry analysis of Ku80 expression on the cell surface. Bone marrow cells were reacted with indicated antibodies and anti-Ku80 antibody as described in “Materials and methods,” and then the expression of surface molecules was analyzed. Prior to the study, each sample had been analyzed by the scattered plot. The results showed that the glycophorin A⁺, CD3⁺, CD20⁺, CD56⁺, or CD36⁺ cells were scattered in gate 1 (G1), and CD14⁺ cells in gate 2 (G2), and that there were no glycophorin A⁺, CD3⁺, CD20⁺, CD56⁺, or CD36⁺ cells in gate 3 (G3). Then the expression of Ku80 on cell surface in gated cells was analyzed. The gate used in each experiment is shown at left-lower side of each plot. (A) Gates used in the experiment and detection of Ku80 on the surface of various cell lineages. (B) Detection of Ku80 on the surface of CD36⁺ bone marrow cells.