Polymerase Chain Reaction (PCR)
1988Method for exponentially amplifying a specific DNA sequence in vitro via repeated cycles of denaturation, primer annealing, and polymerase extension. Kary Mullis conceived the original technique at Cetus Corporation and it was first demonstrated using the Klenow fragment (Saiki et al., Science, 1985), which required adding fresh enzyme every cycle since Klenow is heat-labile. Saiki, Gelfand, Stoffel, Scharf, Higuchi, Horn, Mullis & Erlich, "Primer-Directed Enzymatic Amplification of DNA with a Thermostable DNA Polymerase" (Science 239, 487-491, 1988-01-29, OpenAlex W2032118018, 17,174 citations) replaced Klenow with Taq polymerase (see the linked precursor node), making PCR practical, automatable, and vastly more specific -- the version that actually founded the PCR industry. Mullis won the 1993 Nobel Prize in Chemistry for the original concept. Roche paid Cetus $300M for the PCR/Taq patent rights in 1991. PCR underlies molecular diagnostics, forensics, ancestry testing, and (via RT-PCR) COVID-19 testing.
Originators
- Randall K. Saiki
- Kary B. Mullis
- Henry A. Erlich
Landmark Paper
Checked 2026-09-04 — interim signal only, see docs/BASIC_ROADMAP.md Phase 10
Connections
- is application of RT-PCR COVID-19 Diagnostic Testingbasis: empirical
PCR (specifically its thermostable-polymerase, Taq-based form) is the direct enabling mechanism for RT-PCR COVID-19 diagnostic testing -- reverse transcription of viral RNA into cDNA followed by PCR amplification and real-time fluorescent detection is literally a PCR assay applied to a new target. Corman et al. 2020 (Eurosurveillance 25(8)) is the first published protocol; valid_from is that publication date. Added specifically to close a real connectivity gap: PCR's own node description already named "molecular diagnostics... and (via RT-PCR) COVID-19 testing" as real downstream impact, but the node carried zero edges to any of it -- see docs/APPLIED_BASIC_ENABLEMENT_ADMISSION.md Sec 9 (added 2026-09-10) for the general connectivity requirement this is the first real instance of.