SDS-PAGE gel of purification intermediates and purified rFIXFc monomer. Samples from different steps in the purification of rFIXFc were analyzed by nonreducing SDS-PAGE. Lane 1: SeeBlue Plus Molecular Weight Markers (Invitrogen). Lane 2: Empty lane. Lane 3: Protein A Load. Lane 4: Protein A Eluate. Lane 5: Fractogel DEAE Eluate. Lane 6: Q Seph FF Eluate. Lane 7: Final Bulk Material: rFIXFc. Lane 8: Empty lane. The Final Bulk Material was also analyzed by SDS-PAGE after reduction with 2-mercaptoethanol in lane 9.