Request for information from anons educated in PCR test.
🧐 Research Wanted 🤔
My wife is required to submit to weekly testing for the coof. I asked the testing facility what Cycle Threshold they use for their tests. Here is the response:
**Our test does not use cycle thresholds (Ct). Ct is used for a qPCR test method, whereas we perform rRT-PCR. Our detection is given by flourescently tagged molecules that generate Median Fluorescent Intensity (MFI) based on the viral load of the collected sample. We test for multiple genes within the SARS-CoV-2 genome and have a different threshold for each. I hope that answers your question. **
I 'think' I understand but perhaps there is an anon in here that can give a brief explanation regarding accuracy etc.
They both use cycles. They are trying to "gobbledygook" you.
"The first step of RT-PCR is the synthesis of a DNA/RNA hybrid. [...] The efficiency of the first-strand reaction can affect the amplification process. From here on, the standard PCR procedure is used to amplify the cDNA." https://www.enzolifesciences.com/science-center/technotes/2017/march/what-are-the-differences-between-pcr-rt-pcr-qpcr-and-rt-qpcr?/
"The Ct value is defined as the number of cycles of amplification (using rRT-PCR) required for the fluorescence of a PCR product (i.e. the target/amplicon) to be detected crossing a threshold, which is above the background signal (a low level signal that is present in the assay regardless of whether target is present). When rRT-PCR is performed, a predetermined number of cycles (rounds) of amplification of target (e.g. SARS-CoV-2) nucleic acid occur. If target is present in the specimen then each round of amplification results in a doubling of the amount of target present. As a result, amplification occurs exponentially, producing an exponential curve of amplification" https://www.publichealthontario.ca/-/media/documents/ncov/main/2020/09/cycle-threshold-values-sars-cov2-pcr.pdf?la=en&sc_lang=en&hash=A11E2007A9FA1383556DEF1DBF0F68AB