Patent ID: 7186822

Claim:
A method of preparing a phosphorus-linked oligonucleotide comprising: providing a sample containing a plurality of oligonucleotides, said oligonucleotides linked to a solid support medium, said oligonucleotides comprising a plurality of nucleotides and protected phosphorus linkages wherein at least one of said nucleotides has a 2′-substituent group selected from fluoro, O-alkyl, O-alkylamino, O-alkylalkoxy, protected O-alkylamino, O-alkylaminoalkyl, O-alkyl imidazole, and polyethers; contacting said oligonucleotides with a deprotecting agent to remove phosphorus protecting groups from said oligonucleotides, wherein said oligonucleotides remain linked to said solid support medium during said contacting; said deprotecting reagent comprising at least one amine, the conjugate acid of said amine having a pK a of from about 8 to about 11; optionally washing said oligonucleotides; reacting said oligonucleotides with a cleaving reagent, whereby the oligonucleotides are cleaved from the solid support medium; and with the proviso that at least one of said protected phosphorus linkages is protected by a cyanoethyl protecting group.