PCR and Sanger sequencing
How PCR amplifies a target and Sanger sequencing reads it, what each can and can't detect, and where they still appear in practice (familial variant testing, BCR-ABL1 monitoring, repeat expansions).
Tier 2Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- PCR copies a short stretch of DNA (usually under 1 kb) exponentially, using two primers that flank the target. It makes enough DNA to sequence, size or quantify.
- Sanger sequencing reads the base order of a PCR product, one fragment at a time, with about 99.99% per-base accuracy.
- Together they are the right test for a known variant in a known gene: cascade testing, prenatal testing for a familial variant, or confirming an NGS finding.
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Sources
- Thompson & Thompson Genetics and Genomics in Medicine (9th ed.)Elsevier (Cohn, Scherer and Hamosh, eds), 2023
- Standards and guidelines for the interpretation of sequence variantsGenetics in Medicine (Richards et al., ACMG/AMP, 2015;17:405-24), 2015
- A rigorous interlaboratory examination of the need to confirm next-generation sequencing-detected variants with an orthogonal method in clinical genetic testingJournal of Molecular Diagnostics (Lincoln et al., 2019;21:318-29), 2019
- ACMG technical standards and guidelines for Huntington diseaseGenetics in Medicine (Bean and Bayrak-Toydemir, 2014;16:e2), 2014
- 2025 European LeukemiaNet recommendations for the management of chronic myeloid leukemiaLeukemia (Apperley et al., 2025;39(8):1797-1813), 2025
- Genetic testing resources for cliniciansAU/NZHuman Genetics Society of Australasia
- Last updated
- 14 November 2026
What changed
- 14 November 2026 Personal emails, About story and Australian-style copy