Abstract: Disclosed are methods and compositions for detecting variation in nucleic acids. The disclosed method compares the sequence of a nucleic acid of interest with the sequence of a reference nucleic acid to sensitively identify variations between the sequence of a nucleic acid of interest and the sequence of a reference nucleic acid. The disclosed method generally involves excision and replacement of selected nucleotides in nucleic acid strands hybridized to other strands. In the method, if the excised nucleotide was mismatched with the nucleotide in the other, hybridized strand, then the replacement nucleotide will not be mismatched. If the excised nucleotide was not mismatched with the nucleotide in the other, hybridized strand, then the excised nucleotide is not replaced. This difference allows detection of variation in the nucleic acid of interest.

Abstract: Disclosed are methods and compositions for detecting variation in nucleic acids. The disclosed method compares the sequence of a nucleic acid of interest with the sequence of a reference nucleic acid to sensitively identify variations between the sequence of a nucleic acid of interest and the sequence of a reference nucleic acid. The disclosed method generally involves excision and replacement of selected nucleotides in nucleic acid strands hybridized to other strands. In the method, if the excised nucleotide was mismatched with the nucleotide in the other, hybridized strand, then the replacement nucleotide will not be mismatched. If the excised nucleotide was not mismatched with the nucleotide in the other, hybridized strand, then the excised nucleotide is not replaced. This difference allows detection of variation in the nucleic acid of interest.

Abstract: The present invention provides a method of detecting nucleotide variation within a first nucleic acid, comprising generating a set of single-stranded extension products from a first nucleic acid in the presence of modified nucleotide bases, wherein the extension products incorporate modified nucleotides and thereby limit exonuclease activity to the 3′-terminal nucleotide base, and wherein the extension products have variable lengths, hybridizing the variable length extension products to a reference nucleic acid, contacting the hybridizing nucleic acids with an enzyme which can remove and replace the 3′-terminal nucleotide of the extension products in the presence of selected labeled nucleotides, wherein extension products that terminate with a 3′-nucleotide that does not hybridize with the corresponding position on the reference nucleic acid are replaced with one or more nucleotides that hybridize with the corresponding nucleotides on the reference nucleic acid and wherein those extension pr

Abstract: The present invention provides a method of detecting nucleotide variation within a first nucleic acid, comprising generating a set of single-stranded extension products from a first nucleic acid in the presence of modified nucleotide bases, wherein the extension products incorporate modified nucleotides and thereby limit exonuclease activity to the 3'-terminal nucleotide base, and wherein the extension products have variable lengths, hybridizing the variable length extension products to a reference nucleic acid, contacting the hybridizing nucleic acids with an enzyme which can remove and replace the 3'-terminal nucleotide of the extension products in the presence of selected labeled nucleotides, wherein extension products that terminate with a 3'-nucleotide that does not hybridize with the corresponding position on the reference nucleic acid are replaced with one or more nucleotides that hybridize with the corresponding nucleotides on the reference nucleic acid and wherein those extension products that had a