Fig. 8.

Immunofluorescence stains reveal complex relationships between biomarkers and help distinguish terminal from bisecting GlcNAc. Whole-tissue sections of patients that contain both cancer and adjacent normal regions were investigated. A, H&E-stained tissue sections. B, immunofluorescence (IF) signal above threshold for biomarkers CA19-9 and sTRA overlaid on select complementary mass abundance. C, lectin-stained IF images above threshold. The primary motif for PHA-E (green) is a bisecting GlcNAc with two or three antennae, whereas the primary motif for GSL-II (red) is a terminal GlcNAc presented on an unbranched monosaccharide. D, selected regions of interest in tissues 2815 and 3891 indicate a mixed relationship between lectin binding, mass abundance, and biomarker presence. Regions low and high in biomarker (CA19-9 and sTRA) expression are given for each. CA19-9, carbohydrate antigen 19-9; PHA-E, phaseolus vulgaris erythroagglutinin; sTRA, sialylated tumor-related antigen.