RT-PCR COVID-19 Diagnostic Testing

Reverse-transcription PCR (RT-PCR) used to detect SARS-CoV-2 viral RNA, the global gold-standard COVID-19 diagnostic method from early 2020 onward. First published protocol: Corman, Landt, Kaiser, Molenkamp, Meijer, Chu, Bleicker, Brunink, Schneider, Schmidt, Mulders, Haagmans, van der Veer, van den Brink, Wijsman, Goderski, Romette, Ellis, Zambon, Peiris, Goossens, Reusken, Koopmans & Drosten, "Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR" (Eurosurveillance 25(8), published Jan 23 2020) -- released 16 days after the virus was first sequenced and adopted by the WHO as the basis for global testing protocols within days. Real, massive commercial deployment followed within weeks: the US FDA issued its first COVID-19 diagnostic Emergency Use Authorization (the CDC's own RT-PCR panel) Feb 4 2020, and RT-PCR test kits became a genuine multi-billion-dollar product category (Roche cobas SARS-CoV-2, Abbott, Thermo Fisher TaqPath, Cepheid Xpert Xpress, among many others). Noted for completeness, not to relitigate: the original Corman-Drosten protocol faced a documented methodological critique (an external peer review alleging design flaws, published later in 2020) that the original authors publicly responded to; RT-PCR nonetheless became and remained the dominant global diagnostic method throughout the pandemic, which is the real, undisputed fact this node is admitted on. Added specifically to fix a real connectivity gap on Polymerase Chain Reaction's own node: PCR's description already named COVID-19 testing as real downstream impact, but carried zero edges to any of its named applications -- see docs/APPLIED_BASIC_ENABLEMENT_ADMISSION.md Sec 9.