Updated publication reference for PubMed record(s): 30487799. Glycosylation represents a major post-translational modification of proteins that can influence their structure and function.Telesot immunoglobulin M (IgM) is an especially important product of the immune system because it is the main Abs in seum and plays a critical role against defense infection. However, little is known regarding site-specific N-glycan characteristics in teleost IgM , LC-ESI-MS/MS was used to analysis deglycopeptides and glycopeptides of grass carp serum IgM, and MALDI-MS was used to analysis released carbohydrates by PNGaseF diestion of grass carp serum IgM.