Analysis of Free Oligosaccharides in Urine by High-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Oligosaccharidoses are a group of lysosomal storage disorders characterized by abnormal storage and excretion of incompletely processed glycan structures. As with other inherited metabolic disorders, early diagnosis and initiation of treatment are essential for optimizing outcomes. Biochemical investigation of suspected oligosaccharidoses has traditionally included thin layer chromatography to detect the presence of disease-specific free oligosaccharides in urine; however, this qualitative method has long been known to have limited sensitivity and specificity. In this unit, a quantitative technique for measuring oligosaccharides utilizing high-performance liquid chromatography-tandem mass spectrometry is described, which provides substantial improvements over other methods, in terms of sensitivity and specificity; moreover, it is relatively inexpensive, accessible, and requires significantly less time, effort, sample volume, and reagents to perform. © 2024 Wiley Periodicals LLC. Basic Protocol: Analysis of urinary FOS by HPLC-MS/MS.