Source: cirosantilli/polymerase-chain-reaction

= Polymerase chain reaction
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= PCR
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This is an extremely widely used technique as of 2020 and much earlier.

If allows you to amplify "any" sequence of choice (TODO length limitations) between a start and end sequences of interest which you synthesize.

If the sequence of interest is present, it gets amplified exponentially, and you end up with a bunch of DNA at the end.

You can then measure the DNA concentration based on simple light refraction methods to see if there is a lot of DNA or not in the post-processed sample.

Even <Ciro Santilli> had some contact with it at: <oxford nanopore river bacteria>{full}, see: <oxford nanopore river bacteria/PCR>!

One common problem that happens with PCR if you don't design your primers right is: https://en.wikipedia.org/wiki/Primer_dimer

Sometime it fails: https://www.reddit.com/r/molecularbiology/comments/1kouomw/when_your_pcr_fails_again_and_you_start/
> Nothing humbles you faster than a bandless gel. One minute you’re a scientist, the next you’re just a pipette-wielding wizard casting spells that don’t work. Meanwhile, physicists are out there acting like gravity always behaves. Smash that upvote if your reagents have ever gaslit you.
and a comment:
> PCR = Pray, Cry, Repeat