| When practitioners say "PCR" they don't (usually) just mean amplifying DNA for use as part of the input to another process. What they usually mean is PCR with chemistry that selectively amplifies some specific sequence of DNA. This chemistry has dyes in it which fluoresce when illuminated at some specific wavelength. The point of all this is to answer a "yes/no" question for the presence of some DNA sequence in the sample. This is done at scale with multiple chemistries looking for different DNA sequences. This is also known as "real-time PCR". It's sort of like the biological-assay version of the kid's game "20-questions". If you do it right, it's an enormously powerful detection technique for medical purposes. It gives you your "answer" in a reasonable amount of time on your desk while you wait. That said, there are biological assays that don't need the thermo cycling anymore. These newer assays use more sophisticated chemistry that amplifies at a constant heating temperature. In the simplest terms, they're just heaters combined with a fluorometer. It's potentially MUCH faster than realtime-PCR. In any case, the only real serious money-making business for these instruments is in-vitro diagnostics. That requires FDA approval, and that means a ~10K minimum for the instrument and tens of dollars for the consumables containing the assays, and definitely a pricey service agreement for the instrument (eg Bio-Rad instruments). A distant second money-making business would be research-use-only instruments, but these are not going to be inexpensive little devices. |
I definitely do.
> What they usually mean is PCR with chemistry that selectively amplifies some specific sequence of DNA. This chemistry has dyes in it which fluoresce when illuminated at some specific wavelengt
This is called qPCR (and qRT-PCR, and RT-PCR and ‘Taqman assay’... But it's not called PCR because it's not just PCR).. It has uses outside of diagnostics (which is what it seems you're most familiar with).
Either way, the article is not about qPCR.