Figure 1.
Workflow for slide-based serum and plasma N-glycan profiling by MALDI IMS. (A) Sample preparation steps include diluting the serum or plasma 1:2 in sodium bicarbonate (100 mM, p.H. 8.0) and spotting 1 μL onto a hydrogel-coated slide. The sample spots are put in a humidity chamber for an hour to immobilize to the slide. Carnoy’s solution is used to delipidate the samples for sensitive N-glycan detection. (B) Sample spots are sprayed with PNGase F to enzymatically release N-glycans, and CHCA matrix is applied. (C) Sample spots are imaged in distinct regions by a MALDI-FTICR-MS, allowing for images and abundances of m/z peaks corresponding to N-glycans to be compared across samples.