We optimized each step of histochemical staining and confirmed the reliability and validity of glycomic profiling. Using the optimized procedure, glycomic profiles were obtained with 0.5 mm2 of stained thymic sections (5-μm-thick) from 8-week-old C57BL/6J male mice. The glycomic profiles of Ulex europaeus agglutinin-I (UEA-I)-stained medullary regions showed higher UEA-I signals than those of the morphologically determined medulla regions, indicating the utility of this method for UEA-I(+) cell-selective analysis.
To further evaluate this method, tissue fragments was serially collected from stained and unstained areas of medullary epithelial cell probes (UEA-I and anti-cytokeratin 5 antibody) and a cortex-staining probe (peanut agglutinin). The medullary regions assigned by the three probes showed significantly different glycomic profiles, highlighting the difference in subpopulation recognition among the three probes, which was consistent with previous reports.
In conclusion, our fluorescence LMD-LMA method enabled cell type-selective tissue glycomic analysis of pathological specimens and animal models, especially for glyco-biomarker discovery.