(A) The binding to specific lectins and the sensitivity to distinct glycosydases distinguish different N-glycans. Hybrid and complex N-glycans detected at the plasma membrane (PM) and the Golgi apparatus (Golgi) bind ricin agglutinin (RCA) and wheat germ agglutinin (WGA), respectively, and are hydrolyzed by PNGase. In contrast, core-glycosylated N-glycans are usually specifically localized to the endoplasmic reticulum (ER), bind concanavalin A and galanthus nivalis agglutinin (GNA) and are hydrolyzed by both PNGase and EndoH. (B) Cultured hippocampal neurons (DIV 40) after surface labeling with ConA, GNA, WGA (red) and RCA (green) to identify core-glycosylated (ConA, GNA), complex (WGA) and hybrid (RCA) glycans, respectively. In iii, 'n' and 'g' mark neurons and glial cells, respectively. Note the high reactivity of the neuronal surface to ConA, WGA, GNA and RCA (arrows). In contrast, in iii note the low and high reactivity of glial cells to GNA and RCA, respectively, resulting in a 'green-only' appearance (arrowheads). Scale bars 25 µm. (C) Surface levels of ConA, GNA, RCA and WGA reactive glycans in fibroblasts (COS, white; BHK, light grey; and CHO, dark grey) and in neurons (green). Mean ± SEM. N=27 to 132 cells in 2 experiments. *p<0.05; **p<0.01, ***p<1x10−4; Kruskal-Wallis’s multiple comparison test.