Matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry was performed by a Bruker Ultraflex III TOF/TOF instrument (Bruker Daltonics Inc, Bremen, Germany). Neutral N-glycans were detectable in positive ion reflector mode as [M + Na]+ ions, and acidic N-glycans in negative ion linear mode as [M - H]− ions. Relative molar abundances of neutral and acidic glycan components were assigned based on their relative signal intensities in the mass spectra when analyzed separately as the neutral and acidic N-glycan fraction. The mass spectrometric raw data underwent transformation into the present glycan profiles by removal of the effect of isotopic pattern overlapping, multiple alkali-metal adduct signals, products of elimination of water from reducing oligosaccharides, and other interfering mass spectrometric signals not arising from the sample similarly as previously described (22 (link)). Resultant glycan signals in the glycan profiles were normalized to 100% to allow relative quantitative sample comparison. The glycan signals were then assigned to biosynthetic groups based on their proposed monosaccharide composition (16 (link), 22 (link)), see supplemental Table S1.