due to ever-increasing global diffusion and related socio-economic implications, the detectionof genetically modified organisms (gmos) is very important. in this study, we design a plasmidcontaining two genes in mutated form as construct-specific (cp4 epsps) and event-specific(pd35s). it is applied for quantitative-competitor (qc) pcr as a simple and reliable method forthe detection of gm food....

Aim—To quantify Toxoplasma gondii DNA using a specially constructed artificial template as competitor in a nested polymerase chain reaction (PCR). Methods—The diagnostic assay was a nested PCR employing four primers that amplify part of the single copy gene for the P30 major surface antigen in T gondii. An artificial competitor containing the four primer binding sites was made first by creating...

AIM To quantify Toxoplasma gondii DNA using a specially constructed artificial template as competitor in a nested polymerase chain reaction (PCR). METHODS The diagnostic assay was a nested PCR employing four primers that amplify part of the single copy gene for the P30 major surface antigen in T gondii. An artificial competitor containing the four primer binding sites was made first by creati...

introduction butyrivibrio fibrisolvens strains are presently recognized as the major butyrate-producing bacteria found in the rumen and digestive track of many animals and also in the human gut. in this study we reported the development of two dna based techniques, quantitative competitive (qc) pcr and absolute based real-time pcr, for enumerating butyrivibrio fibrisolvens strains. despite the ...

We recently proposed a quantitative PCR procedure for the absolute measurement of c-erbB-2 oncogene amplification, based on the simultaneous polymerase chain reaction (PCR) amplification of the target gene and of a competitor DNA molecule acting as internal standard. To increase the number of assayable oncogenes and the accuracy of the quantitative comparison of gene amplification degree within...

The use of reverse transcription polymerase chain reaction (RT-PCR) with internal RNA competitive standards (competitors) provides a means for measuring absolute amounts of mRNA transcripts in small numbers of cells. Most quantitative competitive (QC)-RT-PCR methods require analysis of multiple reactions to determine the equimolar point of the products produced from mRNA vs. competitor RNA. Her...

Using dissociation and enhancement time-resolved lanthanide fluorometry, we have developed a quantitative competitive (QC)-PCR for measuring parathyroid hormone-related protein (PTHrP) mRNA after reverse transcription. A cloned PTHrP cDNA target was also modified by deletion of 10 bp and insertion of 21 bp in the midregion of the fragment and cloned for use as a competitor (i.e., internal stand...

BACKGROUND Molecular detection methods for HER2/neu gene amplification include fluorescence in situ hybridization (FISH) and competitive PCR. We designed a quantitative PCR system utilizing fluorescent hybridization probes and a competitor that differed from the HER2/neu sequence by a single base change. METHODS Increasing twofold concentrations of competitor were coamplified with DNA from ce...

The reverse transcription-polymerase chain reaction (RT-PCR) is the most sensitive method used to evaluate gene expression. Although many advances have been made since quantitative RT-PCR was first described, few reports deal with the mathematical bases of this technique. The aim of the present study was to develop and standardize a competitive PCR method using standard-curves to quantify trans...