Processes for quantitative or qualitative detection of single-stranded or double-stranded nucleic acids

A process for detecting qualitatively or quantitatively the presence of a single-stranded or double-stranded nucleic acid of interest in a sample, said process comprising the steps of:

• (a) providing
• (i) a sample suspected of containing said nucleic acid of interest;
• (ii) either at least (a) a first oligonucleotide primer wherein said first oligonucleotide primer comprises a sequence for a phage RNA promoter or (b) a first oligonucleotide primer and a second oligonucleotide primer, wherein either the first oligonucleotide primer, or said second oligonucleotide primer comprises a phage RNA promoter sequence;
• (iii) one or more first ribonucleotides, said first ribonucleotides comprising a first energy transfer element, and one or more second ribonucleotides, said second ribonucleotides comprising a second energy transfer element;
• (iv) reagents for carrying out nucleic acid strand extension and RNA transcription;
• (b) forming a reaction mixture comprising (i), (ii) and (iii) above;
• (c) contacting under hybridization conditions said first nucleic acid primer with one strand of said nucleic acid of interest;
• (d) extending said first oligonucleotide primer to form a primer-extended nucleic acid sequence;
• (e) synthesizing a second nucleic acid strand complementary to said primer-extended nucleic acid sequence or a portion thereof, thereby forming a double-stranded nucleic acid that comprises said phage RNA promoter;
• transcribing from said RNA promoter in said double-stranded nucleic acid formed in step (e) with a cognate phage RNA polymerase to incorporate said first and second ribonucleotides (iii) into transcripts;
• (g) detecting the presence or quantity of said nucleic acid of interest by means of energy transfer between said first energy transfer element and said second energy transfer element;
• wherein said transcribing step (f) is carried out by said RNA promoter sequence in either the primer-extended nucleic acid sequence synthesized in step (d) or the second nucleic acid strand synthesized in step (e).