Stable transfection with the PIG-A cDNA sequence. The GPI-negative JY5 cell line was transfected by electroporation with either the PEB (mock control) plasmid or the PEB/PIGA plasmid. After hygromycin selection, cells were analyzed for the surface expression of CD59, which depends on a functioning PIG-A gene for complete assembly of GPI anchors. The left panel shows results after transfection with PEB, with negative staining observed with both the control antibody (white) and CD59 antibody (grey). The right panel shows results after transfection with PEB/PIGA, with high levels of surface CD59 observed as compared with the control antibody.