2-AB labeled glycans are one of the most referenced glycan standards for biopharmaceutical analysis. Labeled glycans may be analyzed by high-sensitivity fluorescence detection or monitoring of UV-absorbance during various chromatographic and structure sequence analyses, as well as mass spectrometry.
2-AA labeled glycans (2-aminobenzoic acid) are considered to be a superior standard for glycan analysis due to the higher sensitivity of detection as compared to 2-AB labeled glycans.
Permethylation of glycans converts hydrogen groups to methyl groups which renders the glycans hydrophobic; the conversion stabilises sialic acids and can increase signal intensity in mass measurements.
Procainamide labeled glycans can be analyzed by UHPLC, HPLC, ESI-MS, and LC-ESI-MS methods. Because of its improved ionization efficiency compared to 2-AB labeling it can permit identification of minor glycans (<1% relative peak area) by ESI-MS.
APTS labeled glycans (9-Aminopyrene-1,4,6-trisulfonic acid) are commonly used as standards for the analysis of glycoproteins by cappilary electrophoresis (CE). The fluorescent APTS molecule confers a strong negative charge to the APTS labeled glycans resulting in rapid separation via capillary electrophoresis.