Patent ID: 6288221
Filing Date: 2001-09-11
Classification: C07H

Abstract:
An improved method of synthesizing a labeled oligonucleotide comprising:attaching a nucleoside of the oligonucleotide to be synthesized to a solid support through a labile linker arm;said nucleoside containing a removable protecting group attached to a 5' hyroxyl of a sugar group of said nucleoside;removing said protecting group;adding a further nucleoside containing a linker arm and a protecting group to said solid support under conditions where said further nucleoside is coupled to said 5' hydroxyl of said sugar group through said linker arm;optionally capping any uncoupled nucleoside;removing the protecting group of said further nucleoside;repeating the above with further nucleoside derivatives wherein at least one of said further nucleoside contains a detectable label, until a desired oligonucleolide is formed; andcleaving said oligonucleotide from said solid support;wherein the improvement comprises adding at least one dimethoxytrityl, phosphorarridite halonucleoside derivative in place of one of said at least one nucleoside containing a detectable label, wherein said halonucleoside is selected from the group consisting of a C5-halo-pyrimidine, a C8-halo-puine and a C7-halo-7-deazapurine; andlabeling said halonucleoside derivative with a detectable label in place of said halogen during or subsequent to formation of said oligonucleotide.