3 ms·
Yes. I think the device used is a bit more sophisticated than simply obtaining the cycle number where it crosses the threshold. There's a variation of PCR calle
by dsizzle 5y ago
Yes. I think the device used is a bit more sophisticated than simply obtaining the cycle number where it crosses the threshold. There's a variation of PCR called quantitative PCR (qPCR) that measures a fluorescence signal more or less continuously and the growth rate allows one to work backwards to the initial count. Here's a basic description from the maker of the device they used (Taqman) https://www.thermofisher.com/blog/ask-a-scientist/what-is-qpcr/ https://www.thermofisher.com/blog/ask-a-scientist/what-is-qp...
- mlyle 5y agoThere's a lot of ways you can get fancier and more precise quantitative results, sure. The basics is the cycle threshold. The next step further is just to try and come up with a fractional cycle number through interpolation-- e.g. if cycle 20 was not-quite-positive-but-very-close and cycle 21 was strongly positive, that implies a value close to 20, versus if cycle 20 was very far from positive and 21 was just barely over the threshold, that implies the real value is just under 21. And there's further, but diminishing gains from fitting the fluorescence curves.