Glycans are known to cover every type of cells in a species-and state-dependent manner with great structural variety and complexity.Their expressions are often drastically changed in the processes of important biological phenomena, e.g., embryogenesis, differentiation,tumorigenesis, and metastasis l.In fact, most of biomarkers are actually glycans or closely related to their expressions.They include a representative cancer marker, CA19-9 (Sialyl Lewis X) and pluripotent stem cell markers, Tral-60/81, which have been investigated in the process of development of cell surface-specific probes, i.e., antibodies.Recently, we have developed a novel tool for comprehensive analysis of cell surface glycans with a platform of lectin microarray consisting of a panel of lectins with distinct carbohydrate specificity2.For high-sensitive measurement of lectin-glycoprotein interactions, special equipment (scanner),based on a unique evanescent-field activated fluorescence detection principle, has been commercialized.The system, i.e., lectin microarray and the evanescent-type scanner,enables rapid and highly sensitive analysis targeting a variety of cellular glycomes without liberation of glycans from glycoproteins.In this presentation, recent results of differential glycan profiling targeting pluripotent stem cells including induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs) will be described3-5, with emphasis of a novel lectin probe, rBC2LCN.This small recombinant protein (16 kDa) has practical advantage over antibodies (150 kDa) in particular in its cost performance in addition to rigorous specificity to identified carbohydrate markers, H type 1/3 (Fuc□ 1-2Gal□ 1-3GlcNAc/GalNAc), which are carried on hyperglycosylated mucin,podocalyxin6.