Figure 1.

Major N-glycans released from Herceptin (trastuzumab) identified by glycoblotting-assisted MALDI-TOFMS, and some scarce nonfucosylated N-glycoforms supposed to show distinct ADCC could not be detected in this experiment. The m/z values indicate molecular mass of N-glycans tagged with an aminooxy-Trp-Arg reagent for enhancing the ionization potentials of free N-glycans, and asterisks represent peaks of unknown compounds or byproducts generated during on-beads chemical manipulations.^17,18