Stable transduction with the PIG-A cDNA sequence. The GPI-negative JY5 cell line was transduced with supernatants from either the MN (mock control) vector or the MPIN vector. After sorting, cells were analyzed for the surface expression of NGFR, which indicates successful transduction of the retroviral sequence, and CD59, which indicates a functioning PIG-A sequence. Upper left panel: JY5 with MN vector, control antibody. Upper right panel: JY5 with MN vector, NGFR-PE antibody, showing 98% surface expression of NGFR. Lower left panel: JY5 with MPIN vector, control antibodies. Lower right panel: JY% with MPIN vector, CD59-FITC and NGFR-PE antibodies, showing 98% surface expression of both NGFR and CD59, indicating successful transduction of the vector and a functioning PIG-A sequence.