Patent ID: 7618773

Claim:
A method for the selective amplification of a target nucleic acid in a sample comprising the target nucleic acid and at least one non-target nucleic acid, the method comprising selectively amplifying the target nucleic acid compared to the at least one non-target nucleic acid by means of forward and reverse oligonucleotide primers, the forward primer comprising: a primer region that can prime and extend on the target and non-target nucleic acids; and a region that is an inverted repeat of an internal sequence of an amplicon of the at least one non-target nucleic acid but which contains at least one mismatch to the corresponding internal sequence of an amplicon of the target nucleic acid, the inverted repeat region being 5′ of the primer region; wherein during amplification the forward primer extends on the target nucleic acid and the at least one non-target nucleic acid to give rise to first strand products and the reverse primer extends the first strand products to give rise to second strand products; and wherein the inverted repeat region located 5′ of the primer region of the forward primer is copied during second strand synthesis to form a 3′ terminal sequence within the second strand products; and wherein the 3′ terminal sequence of the second strand product corresponding to the at least one non-target nucleic acid anneals to an upstream region of the same product corresponding to the internal sequence of the amplicon and is extended to form a hairpin loop structure that inhibits further amplification of the non-target nucleic acid.