Methods and compositions for increasing efficiency of targeted gene modification using oligonucleotide-mediated gene repair

A method for introducing a gene repair oligonucleobase (GRON)-mediated mutation into a target deoxyribonucleic acid (DNA) sequence in a cell, comprising:

• delivery of a GRON into the cell, wherein the GRON comprises one or more, and preferably 2, 3, 4, 5, or more, of the following characteristics:
• the GRON is greater than 55 bases in length, the GRON optionally comprising two or more mutation sites for introduction into the target DNA;
• the GRON comprises one or more abasic nucleotides
• the GRON comprises one or more 8′oxo dA and/or 8′oxo dG nucleotides;
• the GRON comprises a reverse base at the 3′ end thereof;
• the GRON comprises one or more 2′O-methyl nucleotides at the 5′ or 3′ end thereof,
• the GRON comprises one or more 2′O-methyl RNA nucleotides at the 5′ end thereof,
• the GRON comprises at least two 2′-O-methyl RNA nucleotides at the 5′ end thereof;
• the GRON comprises an intercalating dye;
• the GRON comprises a 5′ terminus cap;
• the GRON comprises a backbone modification selected from the group consisting of a phosphothioate modification, a methyl phosphonate modification, a locked nucleic acid (LNA) modification, a O-(2-methoxyethyl) (MOE) modification, a di PS modification, and a peptide nucleic acid (PNA) modification;
• the GRON comprises one or more intrastrand crosslinks;
• the GRON comprises one or more fluorescent dyes covalently attached thereto;
• and
• the GRON comprises one or more bases which increase hybridization energy.