Patent ID: 7473775

Claim:
An abortive promoter cassette comprising: (a) a self-complementary DNA sequence and an RNA-polymerase binding site; wherein said self complementary sequence is selected from the group consisting of: (i) one contiguous oligonucleotide to which RNA polymerase can bind to form a transcription bubble; (ii) two partially complementary upper and lower oligonucleotides that form a single-stranded transcription bubble region comprising a defined site from which an initiator and a suitable RNA polymerase can synthesize an abortive oligonucleotide product; and (iii) two complementary oligonucleotides that form a transcription bubble region in the presence of an RNA polymerase, which allows for the synthesis of an abortive oligonucleotide product; and (b) a target-specific linker on at least the 3′ or 5′ end of one strand with the proviso that when the target specific linker is a nucleic acid, the linker comprises a single-stranded overhang region of 5 to 40 nucleotides with the further proviso that when the abortive promoter cassette is that of part (a)(i) or (a)(iii), the target specific linker is not a nucleic acid.