Patent ID: 7771934

Claim:
A method of linearly generating multiple copies of a nucleic acid sequence of interest from a template polynucleotide, said method comprising the steps of: (a) hybridizing a first oligonucleotide and a second oligonucleotide to non-overlapping portions of the target polynucleotide, wherein a portion of the target polynucleotide that is hybridizable to the first oligonucleotide is 3′ with respect to the portion of the target nucleotide that is hybridizable to the second oligonucleotide, wherein at least one of said oligonucleotides is a composite primer comprising an RNA portion and a DNA portion such that (i) if said first oligonucleotide is the composite primer, said RNA portion is at the 5′ end of said first oligonucleotide, and (ii) if said second oligonucleotide is the composite primer, said RNA portion is at the 3′ end of said second oligonucleotide, and wherein at least one of said first and second oligonucleotides comprises a sequence that is hybridizable to at least one nucleotide of the sequence of interest; (b) optionally extending the first oligonucleotide with a DNA polymerase that lacks strand displacement activity; (c) attaching the first oligonucleotide and second oligonucleotide to each other when hybridized to said target polynucleotide to generate an attached oligonucleotide combination product; and (d) cleaving the RNA portion of the attached oligonucleotide combination product of (c) with an enzyme that cleaves RNA from an RNA/DNA hybrid such that the cleaved oligonucleotide combination product dissociates from the target polynucleotide, wherein the attached oligonucleotide combination product is of a size that when the RNA is cleaved from the attached oligonucleotide combination product, the cleaved attached oligonucleotide product dissociates from the target polynucleotide, without strand displacement by an enzyme, under essentially the same conditions as those for hybridization of the composite oligonucleotides to the target and the attachment of the hybridized oligonucleotides, (e) repeating steps (a)-(d) whereby multiple copies of the sequence of interest are produced, wherein said first or second oligonucleotide hybridize only to the template polynucleotide and not to said cleaved oligonucleotide combination product.