Fig. 3

Biological reproducibility and sialylation status of EPO clones expressing bi-antennary N-glycans. a Deconvoluted mass spectra of EPO from two biological replicate clones, C11 (top) and C12 (bottom) exhibiting variable degree of O-glycosite occupancy (Hex₁₅HexNAc₁₂F₃ glycoproteoform), b Comparison of sialylation on EPO purified from clone C08 (mgat4A/4B/5 KO) and C12, whereby the latter has an additional st3gal4/6 KO. c Deconvoluted native mass spectrum of sialidase treated EPO purified from the C12 clone. The depicted glycan composition corresponds to the total glycan content of the most abundant mass peak. Main glycoproteoforms are color coded, wherein each color corresponds to a unique Hex_x+3HexNAc_xF₃ composition, and the numbers above the annotated peaks indicate the number of sialic acid residues