Abstract: The invention concerns compounds which have a chromophore and a group capable of binding to streptavidin or/and avidin and which are suitable for binding to molecules containing an aldehyde, ketone, hemiacetal or/and hemiketal group. In addition the invention concerns conjugates formed from these compounds as well as a method for the detection or isolation of carbohydrates or glycan receptors by means of such conjugates.

Abstract: A double- or single-stranded oligonucleotide comprising one or more respectively inter- or intra-oligonucleotide covalent cross-linkages, wherein the or each covalent linkage consists of an amide bond between a primary amine group of one strand and a carboxyl group of the other strand or the same strand, respectively, said primary amine group being directly substituted in the 2′ position of the strand nucleotide monosaccharide ring, and said carboxyl group being carried by an aliphatic spacer group substituted on a nucleotide or nucleotide analog of the other strand or the same strand, respectively. A method for preparing such oligonucleotides, and nucleotide or non-nucleotide synthons useful for preparing an oligonucleotide of the above kind, are also disclosed.