Patent ID: 7368265

Claim:
A method of amplifying selected DNA fragments, the method comprising the steps of: ligating to a first end of each DNA fragment a first hairpin adaptor and to a second end of each DNA fragment a second hairpin adaptor to form an augmented sequence, the first and second hairpin adaptors each having a loop region and a duplex region, the duplex region of each first hairpin adaptor containing a promoter sequence oriented so that transcription proceeds toward its loop region; combining the augmented sequence, an RNA polymerase, a reverse transcriptase, a DNA polymerase, and primers specific for one or more primer binding sites within the augmented sequence under reaction conditions such that the RNA polymerase generates transcripts from the augmented sequence, primers anneal to at least one primer binding site and are extended by the reverse transcriptase to produce first complementary DNA strands, primers anneal to first complementary DNA strands and are extended by the DNA polymerase to form second DNA strands, thereby amplifying the selected DNA fragments.