Impact of Sf-fdl editing on N-glycan processing. N-glycans were isolated from hEPO produced by Sf9, SfFDLt1 polyclonal, or SfFDLt1 monoclonal cl#32 cells, derivatized, and profiled by MALDI-TOF-MS, as described in Materials and Methods. All molecular ions were detected as [M + Na]+, assigned and annotated using the standard cartoon symbolic representations.