Robustness and repeatability of GlycoWorks RapiFluor-MS IgG N-glycan profiling in a long-term high-throughput glycomic study.

Protein glycosylation is the attachment of a carbohydrate moiety to a protein backbone affecting both structure and function of the protein. Abnormal glycosylation is associated with various diseases, and some of the changes in glycosylation are detectable even before symptom development. As such, glycans have emerged as compelling new biomarker candidates. A wide range of analytical methods exist for small-scale glycan analyses. However, there is a growing need for highly robust and reproducible high-throughput techniques that allow for large-scale glycoprofiling. Here, we describe the evaluation of robustness and repeatability of immunoglobulin G (IgG) N-glycan analysis using the GlycoWorks RapiFluor-MS N-Glycan Kit followed by hydrophilic interaction ultra-high-performance liquid chromatography (HILIC-UHPLC) from 335 technical replicates of human plasma randomly distributed across 67 96-well plates. The data was collected over a 5-month period using multiple UHPLC systems and chromatographic columns. Following relative IgG N-glycan quantification in acquired chromatograms, data analysis showed that the most abundant peaks that together made up for three-fourths of the detected IgG N-glycome all had coefficients of variation (CVs) lower than 2%. The highest CVs ranging from 16 to 29% accompanied low abundance glycan peaks with the individual relative peak area below 1% that together made up for <2% of the detected IgG N-glycome. These results show that the tested method is very robust and repeatable, making it suitable for the IgG N-glycan analysis of a large number of samples in a high-throughput manner over a longer period of time.