Patent ID: 7041816

Claim:
A method of preparing a sample of a phosphate linked oligonucleotide having a substantially reduced content of acrylonitrile adduct comprising: providing a sample containing a plurality of oligonucleotides, said oligonucleotides linked to a solid support medium, said oligonucleotides having a plurality of protected phosphorus linkages wherein at least one protected phosphorus linkage is a protected phosphorothioate linkage; contacting said oligonucleotides with a deprotecting agent to remove phosphorus protecting groups from said oligomers, wherein 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 pKa of from about 8 to about 11; said deprotecting reagent optionally further comprising one or more solvents selected from the group consisting of alkyl solvents, haloalkyl solvents, cyanoalkyl solvents, aryl solvents and aralkyl solvents; optionally washing said oligonucleotides; and reacting said oligonucleotides with a cleaving reagent.