Fig. 5.

Improved detection of N-glycans using the MRM method. N-glycans were detected using Q-TOF MS (pale blue or pale red) and QQQ MS (MRM mode, blue or red). The improved detection of representative neutral N-glycans Hex₄HexNAc₄, Hex₄HexNAc₄dHex₁ and Hex₃HexNAc₅dHex₁ are shown in a, and the improved detection of representative sialylated N-glycans Hex₅HexNAc₃dHex₁NeuAc₁, Hex₅HexNAc₄dHex₁NeuAc₁ + SO₃ and Hex₆HexNAc₃NeuAc₁ are shown in b. The signal intensities of N-glycans obtained using the MRM method were increased by up to 180-fold compared with those obtained with Q-TOF MS. Notably, the S/N of the acidic N-glycans obtained using MRM increased by ~10-fold to 1000-fold compared with that obtained with Q-TOF MS