Abstract: A chimera oligonucleotide is provided that can be used in a process for obtaining transcripts and/or amplification of a target sequence of a nucleic acid, having, at its 3' end, a downstream sequence. The oligonucleotide comprises successively, from 5' to 3', 1) a first oligonucleotide segment, of the DNA type, comprising a sense sequence of a promoter of an RNA polymerase, 2) a second oligonucleotide segment, of the DNA type, capable of hybridizing with the downstream sequence, and 3) a third oligonucleotide segment, of the RNA type, capable of hybridizing with a part of the target sequence contiguous to the downstream sequence, the third segment being blocked at 3'. A process using the chimera oligonucleotide and an enzyme system containing DNA polymerase activity, RNA polymerase activity, and a third activity, for example, an RNase H activity provides transcription products of the target.

Abstract: A procedure for detecting single-stranded nucleotide sequences in a sample is disclosed wherein a passively fixed capture probe is used in concert with a non-radioactively labelled detection probe in a sandwich hybridization technique.

Abstract: An RNA amplification method is particularly useful for diagnosing bacterial or viral infections or genetic disorders and for cell typing. The method includes the steps of denaturing a solution containing RNA, synthesizing a first cDNA strand from a suitable primer in the presence of reverse transcriptase, denaturing the heteroduplex formed, synthesizing a second cDNA strand from a second primer in the presence of DNA polymerase and then subjecting the cDNA formed to a sufficient number of amplification cycles. All the reactants and solvents are first placed in the same container to provide a single manipulation step that avoids the risk of contamination.