title: Novel, ultrasensitive, Q-beta replicase-amplified hybridization assay for detection of Chlamydia trachomatis.
abstract: A sensitive, nonisotopic hybridization assay termed "dual capture" is described. The assay rapidly and specifically detects very low levels of target nucleic acids and organisms. The assay is based on the principles of sandwich hybridization, reversible target capture, and Q-Beta replicase amplification. The assay can be completed in less than 4 h, and in the described model format, it detects Chlamydia trachomatis rRNA or rDNA. Up to 96 samples can be analyzed simultaneously. The assay employs two types of probes: a test-specific capture probe, which mediates the cycling of the target probe complex on and off derivatized magnetic beads, and a replicatable RNA detector molecule containing a sequence complementary to and adjacent to the capture probe site on the target. Following reversible target capture, detection of the signal is accomplished by replication of the detector molecule by Q-Beta replicase in the presence of propidium iodide. A specific assay signal can be detected from as few as 1,000 molecules above the background. In a limited study of 94 urogenital samples the assay detected five of the six culture-positive samples and did not detect the C. trachomatis target in 85 of the 88 culture-negative samples.
authors.affiliation: GENE-TRAK Inc., Framingham, Massachusetts 01701.
authors.forename: J S
authors.initials: JS
authors.lastname: Shah
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Smith
authors.forename: S
authors.initials: S
authors.lastname: Popoff
authors.forename: G
authors.initials: G
authors.lastname: Radcliffe
authors.forename: W J
authors.initials: WJ
authors.lastname: O'Brien
authors.forename: G
authors.initials: G
authors.lastname: Serpe
authors.forename: D M
authors.initials: DM
authors.lastname: Olive
authors.forename: W
authors.initials: W
authors.lastname: King
mesh_terms: D001483:Base Sequence; D002692:Chlamydia trachomatis / Q000235:genetics / Q000302:isolation & purification*; D005784:Gene Amplification; D006801:Humans; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D011777:Q beta Replicase; D012329:RNA, Bacterial / Q000032:analysis; D012335:RNA, Ribosomal / Q000032:analysis / Q000235:genetics; D012680:Sensitivity and Specificity
chemical_list: D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D011777:Q beta Replicase