Abstract: Methods and kits for relating initial amounts of target nucleic acids present in a sample to target-specific amplification products. It has been discovered that the transcription-mediated amplification system is capable of producing a quantitative relationship between target input and target-specific output. Further, the the present invention relates to methods for carefully controlling this relationship resulting in an unexpectedly high degree of reproducability. Also described are useful methods for extending the dynamic range of transcription-based amplification systems.

Abstract: A method, composition and kit for amplifying a target nucleic acid sequence under conditions of substantially constant temperature, ionic strength, and pH and using only a single promoter-primer. To effect the amplification, a supply of a single promoter-primer having a promoter and a primer complementary to the 3'-end of the target sequence, and a reverse transcriptase and an RNA polymerase are provided to a mixture including the target sequence; the amplification proceeds accordingly. The invention is useful for generating copies of a nucleic acid target sequence for purposes that include assays to quantitate specific nucleic acid sequences in clinical, environmental, forensic and similar samples, cloning and generating probes.

Abstract: A method for preparing probes, as well as several probes for use in qualitative or quantitative hybridization assays are disclosed. The method comprises constructing an oligonucleotide that is sufficiently complementary to hybridize to a region of rRNA selected to be unique to a non-viral organism or group of non-viral organisms sought to be detected, said region of rRNA being selected by comparing one or more variable region rRNA sequences of said non-viral organism or group of non-viral organisms with one or more variable region rRNA sequences from one or more non-viral organisms sought to be distinguished. Hybridization assay probes for Mycobacterium avium, Mycobacterium intracellulare, the Mycobacterium tuberculosis-complex bacteria, Mycoplasma pneumoniae, Legionella, Salmonella, Chlamydia trachomatis, Campylobacter, Proteus mirabilis, Enterococcus, Enterobacter cloacae, E. coli, Pseudomonas group I, Neisseria gonorrhoeae, bacteria, and fungi also are disclosed.