Patent ID: 7258854

Claim:
An isolated cell obtained by a method of targeted chromosomal sequence alteration, the method comprising: introducing a sequence-altering oligonucleotide into the cell in vitro, wherein said sequence-altering oligonucleotide: is a single-stranded nonhairpin oligonucleotide 17-121 nucleotides in length; has an unmodified DNA domain of at least 8 contiguous deoxyribonucleotides; is fully complementary in sequence to a first strand of the cell's chromosomal DNA at a chromosomal target sequence, except for one or two mismatches positioned (i) within said oligonucleotide's unmodified DNA domain and (ii) at least 8 nucleotides from said oligonucleotide's 5′ and 3′ termini; has chemical modifications selected from the group consisting essentially of a terminal locked nucleic acid (LNA), a terminal 2′-O′Me base analog, at least three terminal phosphorothioate linkages, and combinations thereof, whereby said introduced oligonucleotide directs sequence alteration by the cellular repair enzyme machinery at said chromosomal target sequence; and wherein the cell comprises the sequence-altering nucleotide.