Glucose unit index (GUI) of permethylated glycans for effective identification of glycans and glycan isomers

摘要: Retention time is the most common and widely used criterion to report separation of glycans using Liquid Chromatography (LC), but it varies across different columns, instruments laboratories. This variation problematic when inter-laboratory data compared. Furthermore, influences reproducibility hampers efficient interpretation. In our endeavor overcome this variance, we propose use Glucose Unit Index (GUI) on C18 PGC column-based reduced permethylated glycans. GUI has previously been utilized for retention normalization native labeled We evaluated method with derived from model glycoproteins fetuin ribonuclease B (RNase B), then implemented human blood serum generate isomeric glycan libraries. values compositions were calculated respect glucose units dextrin, which was employed as an elution standard. The validated three LC systems (UltiMate 3000 Nano UHPLC systems) in two laboratories ensure reliability method. Applicability real samples demonstrated breast cancer cell lines. A total 116 N-glycans separated a column 134 compiled library. Overall, established demonstration reproducible inter- intra-laboratory would aid future development automated identification methods.