Quantification of human immunodeficiency virus type 1 (HIV-1) RNA in plasma has rapidly become an important tool in basic HIV research and in the clinical care of infected individuals. Here, a quantitative HIV assay based on competitive reverse transcription-PCR with multiple competitors was developed. Four RNA competitors containing identical PCR primer binding sequences as the viral HIV-1 RNA...

The present studies demonstrate a theoretical and practical framework for the accurate quantitation of gene expression in RNA extracted from microscopic tissue samples. The approaches are developed around competitive RT-PCR techniques. Assay performance has been examined and validated at both the RT and PCR steps. Our analysis of RT transcription efficiency for a number of native and competitor...

DNA fragments used as standards in competitive PCR were precisely calibrated using HPLC and commercially available DNA molecular mass markers. The accuracy of calibration was reflected by data that differed by only 2% from the mean when two independently purified and calibrated competitor preparations were compared. Highly dilute competitor solutions were stable at -20 degrees C for up to 1 yea...

Growth of Salmonella enterica was studied in model mixed cultures with Citrobacter freundii or Escherichia coli in buffered peptone water (BPW) and in Rappaport-Vassiliadis medium with soya (RVS) with modified concentrations of MgCl2 and malachite green, and at modified incubation temperatures. Selected S. enterica strains were inoculated in BPW (10(0) cfu/ml) together with selected strains of ...

Benzene, toluene, xylenes, phenol, naphthalene, and biphenyl are among a group of compounds that have at least one reported pathway for biodegradation involving catechol 2,3-dioxygenase enzymes. Thus, detection of the corresponding catechol 2,3-dioxygenase genes can serve as a basis for identifying and quantifying bacteria that have these catabolic abilities. Primers that can successfully ampli...

We report on the development of a fully automated real-time PCR assay for the quantitative detection of hepatitis B virus (HBV) DNA in plasma with EDTA (EDTA plasma). The MagNA Pure LC instrument was used for automated DNA purification and automated preparation of PCR mixtures. Real-time PCR was performed on the LightCycler instrument. An internal amplification control was devised as a PCR comp...

Competitive reverse-transcription PCR (RT-PCR) techniques for quantification of gene expression employ titrations in which the products of multiple PCRs must be separated, analyzed and quantified to compute gene expression in a single sample. We have employed a novel, ion-pair reversed-phase HPLC (IP-RP-HPLC) system to analyze and quantify RT-PCRs performed with mutant RNA internal standards. P...