Patent ID: 6313284
Filing Date: 2001-11-06
Classification: C07H,C12Q

Abstract:
A method for preparing an immobilized oligonucleotide having a free 3'-end comprising:(i) preparing an oligonucleotide attached in a first position to a solid support via its 3'-end and having a free 5'-end;(ii) binding said oligonucleotide via a second position along said oligonucleotide remote from the 3'-end to the solid support by reacting a nucleophilic reactive function with an electrophilic reactive function to form a stable bond; and(iii) selectively releasing the 3'-end of the oligonucleotide from the solid support to obtain the oligonucleotide attached to the solid support in said second position in a reversed orientation having a free 3'-end, wherein the nucleophilic reactive function is hydroxyl and the electrophilic reactive function is X-B, wherein X is a phosphodiester and B is a group removable from a phosphotriester to form a phosphodiester, wherein said B is selected from the group consisting of 2-chlorophenyl, 2,4-dichlorophenyl, 2-nitrophenyl, 4-nitrophenyl, 4-nitrophenylethyl and 2-cyanoethyl.