Protocols for Assessing Storage Stability and Solubility of Released N‐Linked Glycans Prior to Mass Spectrometry Analysis

Released N‐linked glycans are frequently stored between enzymatic release, cleanup, and LC–MS analysis, yet storage solvent and freeze–thaw handling are often reported incompletely or omitted. This unit provides a procedure for determining, within a given laboratory and for a given glycan preparation, whether a selected storage condition preserves analytical performance prior to LC–ion mobility–mass spectrometry (LC–IM–MS). The workflow compares matched aliquots prepared from a single cleared glycan stock, using extracted ion chromatogram signal intensity, chromatographic peak shape, visible precipitation, and replicate precision as acceptance criteria, assessed both before and after a controlled freeze–thaw cycle. A worked example comparing 0.1% (v/v) formic acid in water with 50:50 acetonitrile:water is presented to demonstrate the workflow. The aqueous condition retained LC–IM–MS signal after one freeze–thaw cycle, while the acetonitrile‐containing condition showed substantial post‐thaw signal loss despite acceptable pre‐freeze performance. This example illustrates the magnitude of effect that storage solvent can produce and is not presented as a general storage recommendation, since susceptibility is both structure dependent and platform dependent. The protocols are intended for laboratories analyzing released N‐linked glycans from glycoproteins or biological samples and can be applied to PGC‐, reversed‐phase‐, or HILIC‐based LC–MS workflows, with solvent adjustment performed immediately before injection rather than during long‐term storage. © 2026 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1 : Solvent selection and solubility assessment of released N‐linked glycans before LC–IM–MS analysis Basic Protocol 2 : Freeze–thaw stability evaluation and long‐term aqueous storage of released N‐linked glycan stocks Support Protocol : Preparation of single‐use glycan aliquots and pre‐injection quality control