Hydrazino, oxyamino and carbonyl-based reagents and methods for
incorporation into oligonucleotides during their solid phase synthesis
are provided. Modified oligonucleotides are provided that incorporate the
reagents provided herein. Immobilized oligonucleotides and
oligonucleotide conjugates that contain covalent hydrazone or oxime
linkages are provided. Methods for preparation of surface bound
oligonucleotides are provided. Methods for the preparation of
oligonucleotide conjugates are also provided.