Methods (molecular, IHC, frozen)
Molecular
PCR
PCR general
Topic Completed: 1 January 2010
Minor changes: 14 December 2020
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PubMed Search: Polymerase chain reaction[TI] history free full text[sb]
Table of Contents
Pre-PCR history | Pre-PCR history | Initial discovery of PCR | Later PCR related workCite this page: Shackelford R. PCR general. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/MolecularPCRhistory.html. Accessed January 18th, 2021.
Pre-PCR history
- Common technique used to amplify very small amounts of a specific DNA sequence, even a single copy, into millions or up to 100 billion copies in a short time (Wikipedia: Polymerase Chain Reaction [Accessed 4 June 2018])
- Technique works best on short DNA sequences of 100 to 1,000 base pairs and employs dNTPs, Taq DNA polymerase, oligonucleotides, specific buffer conditions and thermal cycling
- PCR has many variations and is a fundamental tool in medical research and molecular pathology
- Developed in 1983 by Kary Mullis (Wikipedia: Kary Mullis [Accessed 4 June 2018]), who won the Nobel Prize in Chemistry in 1993 for this work
- Presently over 350,000 papers have been published which use or refer to this technique
Pre-PCR history
- Prior to PCR technology, obtaining multiple copies of a specific DNA sequence was commonly done but often laborious
- Most protocols involved:
- Isolating many copies of the sequence(s) desired
- Cloning the DNA into a viral or bacterial plasmid vector
- Transfecting, selecting and growing the bacteria carrying the DNA and vector
- Reisolating the desired sequence(s) from bacterial cultures by purifying and cutting the plasmids
- Limitations:
- Procedure could take several weeks
- Often difficult to get pure DNA / gene sequences from the complex mixtures typically used to obtain DNA samples
Initial discovery of PCR
- Conceived in 1983 by Kary Mullis (Wikipedia: Kary Mullis [Accessed 4 June 2018]), working at Cetus Corporation as a chemist
- Initial idea was to use a pair of primers to bracket the desired DNA sequence and to copy it repeatedly using DNA polymerase
- Mullis received a $10,000 bonus from Cetus for the invention; Cetus later sold the patent to Roche for $300 million; Mullis may have received additional money for testifying on behalf of Cetus in a patent lawsuit
