Flow cytometric analyses of pI2E- versus pDI2E-transfected K562 cells.

K562 cells were transfected with pI2E (DOK1⁻) or pDI2E (DOK1⁺) DNA and grown in G418-containing media. Stable transfectants were stained with serum containing antibodies to Dombrock antigens (Gy^a, Do^a, Jo^a, and Hy), counterstained with PE-labeled F(ab′)₂ fragments, and analyzed by flow cytometry. The numbers shown at the upper right of each panel are the mean fluorescence values (PE channel) of the transfected cells. The control serum contained no Dombrock antibodies, as measured by indirect hemagglutination assays.