| abstract |
Sequence specific phosphorothioate oligonucleotides comprising nucleoside units which are joined together by either substantially all Sp or substantially all Rp phosphorothioate intersugar linkages are provided. Such sequence specific phosphorothioate oligonucleotides having substantially chirally pure intersugar linkages are prepared by enzymatic synthesis from nucleoside 5'-O-(1-thiotriphosphates). |