Patent ID: 6166198
Filing Date: 2000-12-26
Classification: C07H

Abstract:
A method of preparing a coupled oligonucleotide, YZ, comprising the steps of:(a) providing a plurality of identical first nucleotidic segments, Y, in solution, each of said first segments comprising exactly one, two, three, four, six or eight nucleosides, each of said first segments having a reactive functional group, a, which is a phosphoramidite group,(b) providing a plurality of identical second nucleotidic segments, Z, in solution, each of said first segments comprising exactly one, two, three, four, six or eight nucleosides, each of said second segments having two non-identical reactive functional groups, b and c, which are a secondary alcohol group and a primary alcohol group, respectively;(c) reacting said first and second segments in solution under conditions whereby said phosphoramidite group reacts with said secondary alcohol group and said primary alcohol group to form a covalent internucleoside linkage joining Y and Z, thereby producing a first linkage isomer, YZ-b, which retains a residual secondary alcohol group, b, and a non-identical second linkage isomer, YZ-c, which retains a residual primary alcohol group, c;(d) reacting a mixture of said YZ linkage isomers, or derivatives thereof, with a selective capping reagent, in solution, whereby said residual secondary alcohol group, b, of said YZ-b linkage isomer remains selectively unchanged, and said residual primary alcohol group, c, of said YZ-c linkage isomer is selectively capped.