A review of two key documents by the FDA. High Points:
PCR tests, by dozens, and then hundreds of manufacturers, were not based off an actual clinical specimen. Instead, manufacturers were instructed to, in essence, come up with their best guess of covid-ish for their tests to detect, through any number of "contrived" means (Yes, the FDA literally describes them as "contrived." Multiple times)
Once the FDA did allegedly come up with a good specimen, only a couple of months into the exercise, they did not make manufacturers then create tests based on that standard.
So all along, until the PCR tests were discontinued from emergency use at the end of 2021, they varied so widely that the FDA literally says it doesn't make much sense to even compare them.
But, to the extent they did - by comparing their performance, in sensitivity to detect the standard specimen, PCR tests varied by over 3,000-fold, depending on manufacturer!
Thanks for coming on this ongoing journey of discovery and emphasis of important truths and distinctions.