Synthesis and clusterization of Galbeta(1-->3)[NeuAcalpha(2-->6)]GlcNAcbeta(1-->2)Man motif of the N-glycan, as the molecular probes for their biological evaluation, are reported. Key step is the quantitative and the completely alpha-selective sialylation of the C5-azide N-phenyltrifluoroacetimidate with the disaccharide acceptor, Galbeta(1-->3)GlcNTroc. Clusterization of the 16 molecules of trisaccharide motif was also achieved by the 'self-activating click reaction'. These probes could efficiently be labeled by biotin and/or other fluorescence- or radioactive reporter groups through either cross metathesis, acylation, Cu(I)-mediated Huisgen [2+3]-cycloaddition, or the azaelectrocyclization to utilize the various biological techniques.