Patent Number: 6,310,198

Title: Extremely high purity oligonucleotides and methods of synthesizing themusing dimer blocks

Abstract: The present invention comprises an improved method of synthesizingoligonucleotides. The method comprises employing dinucleotides (or "dimerblocks") as the basic synthetic unit building block. The method results inextremely high purity oligonucleotides in which the N-1 content is verylow, generally less than 1-2% of the full length, N, oligonucleotide. Wehave found that synthesis using dinucleotide phosphorothioates results inoligonucleotides having very little phosphodiester content. Furthermore,we have found that the amount of dimer required in each coupling step canbe less than about 6 and is preferably about 2 equivalents. Synthesis ofoligonucleotides according to the dimer block approach described hereincan also be conducted without the capping step that has heretofore beendeemed necessary after each coupling.

Inventors: Tang; Jin-Yan (Shrewsbury, MA), Bongle; Nandkumar (Shrewsbury, MA), Gonzalez; Jose (Westborough, MA), Schwartz; Warren E. (Boxborough, MA)

Assignee:

International Classification:

Expiration Date: 10/32013