Versatile strategy for oligonucleotide derivatization. Introduction of lanthanide(III) chelates to oligonucleotides

[GRAPHICS] Novel nucleosidic phosphoramidite blocks were synthesized by a Mitsunobu re action between 2'-deoxy-5'-O-(4,4'-dimethoxytrityl)uridine and a primary al cohol containing a conjugate group in its structure (a protected functional group, an organic dye, or a precursor of a lanthanide(III) chelate) follow ed by phosphitylation. They were used in machine-assisted DNA synthesis in the standard manner. A slighty modified deprotection procedure was used for the preparation of oligonucleotide conjugates tethered to lanthanide(Ill) chelates. For the latter application one non-nucleosidic block was also syn thesized.