Patent ID: 7413857

Claim:
A method for amplifying a target nucleic acid sequence comprising a target nucleic acid, the method comprising the steps of: a) hybridizing a riboprimer to a DNA template comprising the target nucleic acid sequence, wherein said riboprimer comprises: i) only ribonucleotides, or ii) only purine ribonucleotides and only pyrimidine nucleotides, wherein at least one of the pyrimidine nucleotides is a pyrimidine 2′-deoxyribonucleotide having a non-canonical substituent, which substituent is neither an H nor an OH, on the 2′-position of the deoxyribose sugar moiety; b) extending the riboprimer with a DNA polymerase that lacks 5′-to-3′ exonuclease activity; and c) cleaving the annealed riboprimer with an RNAse H enzyme such that another riboprimer hybridizes to the template and repeats primer extension, whereby multiple copies of the complementary sequence of the target nucleic acid sequence are produced.