Abstract: A method of genotyping single nucleotide polymorphisms (“SNP”) and point mutations in nucleic acid based on chain extension by polymerase. This invention is based on the fact that the nucleoside immediately 5? adjacent to any SNP/point mutation site is known, and the neighboring sequence immediately 3? adjacent to the site is also known. A primer complementary to the sequence directly adjacent to the SNP on the 3? side in a target polynucleotide is used for chain elongation. The polymerase reaction mixture contains one chain-terminating nucleotide having a base complementary to the nucleotide directly adjacent to the SNP on the 5? side in the target polynucleotide. An additional dNTP may be added to produce a primer with the maximum of a two-base extension. The resultant elongation/termination reaction products are analyzed for the length of chain extension of the primer, or for the amount of label incorporation from a labeled form of the terminator nucleotide.

Abstract: A method of genotyping single nucleotide polymorphisms (“SNP”) and point mutations in nucleic acid based on chain extension by polymerase. This invention is based on the fact that the nucleoside immediately 5′ adjacent to any SNP/point mutation site is known, and the neighboring sequence immediately 3′ adjacent to the site is also known. A primer complementary to the sequence directly adjacent to the SNP on the 3′ side in a target polynucleotide is used for chain elongation. The polymerase reaction mixture contains one chain-terminating nucleotide having a base complementary to the nucleotide directly adjacent to the SNP on the 5′ side in the target polynucleotide. An additional dNTP may be added to produce a primer with the maximum of a two-base extension. The resultant elongation/termination reaction products are analyzed for the length of chain extension of the primer, or for the amount of label incorporation from a labeled form of the terminator nucleotide.