Glycosylations – the modification of proteins by sugar moieties – are an abundant form of post-translational processing in eukaryotic and prokaryotic systems. Dependent on their enormous structural diversity, glycosylations are involved in manifold functions – control of protein folding, cellular trafficking, modulation of protein-protein interactions as well as protein activity and stability, to name but a few. Defects in glycosylation patterns may cause complicated metabolic disorders which often require sophisticated diagnosis and medical care. Although the impact of glycosylations was known for decades, their analysis requires an array of specialized techniques to cope with the complexity of this task. Therefore, at ISAS enhanced innovative methods for glycoprotein and carbohydrate analysis are developed. Based on state-of-the-art chromatographic and mass spectrometric techniques, these studies are aimed at the qualitative as well as quantitative analysis of modification sites and their attached carbohydrate structures.