Discovery of PCR & RT-PCR revolutionized Molecular Biology in the 21st Century

Discovery of PCR & RT-PCR revolutionized Molecular Biology in the 21st Century


  • Post By : Bijoy Varma, Marketing & Strategy, ABDOS

  • Source: Abdos Life Science

  • Date: 04 May,2022

PCR has revolutionized the molecular biology field, giving rise to many advantageous techniques that allow the analysis of different nucleic acids. Polymerase Chain Reaction was developed by Kary Mullis in 1983.

PCR overview

Polymerase chain reaction (PCR) is a technique used for detecting, quantifying and amplifying nucleic acids. The basic PCR mechanism involves the use of an enzyme called DNA polymerase to synthesize complementary strands of DNA from a denatured double-stranded template, effectively doubling the original sample with every cycle of the PCR reaction. This molecular copying operates through cycles of thermal reactions enabled by an assembly of biochemical reagents, and amplifies a few copies of DNA to millions.

Amplified DNA can then be analyzed qualitatively (for its presence), quantitatively (by amount) or sequentially (for its genetic code), and used in downstream molecular biology applications.

PCR has revolutionized the molecular biology field, giving rise to many advantageous techniques that allow the analysis of different nucleic acids. Polymerase Chain Reaction was developed by Kary Mullis in 1983. Kary Banks Mullis (December 28, 1944 – August 7, 2019) was an American biochemist. In recognition of his role in the invention of the polymerase chain reaction (PCR) technique, he shared the 1993 Nobel Prize in Chemistry with Michael Smith and was awarded the Japan Prize in the same year.


From the time of their discovery DNA polymerases have paved the way to new understandings of how DNA is replicated and how it is transcribed.

They have also been crucial to the development of DNA sequencing and PCR, upon which much of modern biotechnology is built. Today polymerases are the core tools for DNA labelling, sequencing and amplification. DNA polymerases are also intrinsic components for the development of molecular diagnostics for personalised medicine. They are at the forefront of techniques to detect genomic alterations that can cause diseases like cancer or cause patients to experience adverse reactions to drugs.

Taq DNA polymerase was purified from the bacterium Thermus aquaticus in 1976 which was found to live in the hot springs of Yellowstone Park in Wyoming by Thomas Brock in 1965. The advantage of Taq is that it can withstand very high temperatures. This makes it suitable for use in PCR.


Polymerase does not create a novel DNA strand from scratch. Instead it synthesizes a new strand of DNA based on the template of two existing DNA strands. It does this with the help of another enzyme, called helicase, which unwinds the double helix structure of the DNA molecule into two single DNA strands. In addition to a template strand, polymerases require a primer to function. This is a fragment of nucleic acid that serves as the starting point for DNA replication. The primer, often a short strand of RNA, needs to be complementary to the template. DNA polymerase works by sliding along the single strand template of DNA reading its nucleotide bases as it goes along and inserting new complementary nucleotides into the primer so as to make a sequence complementary to the template. DNA polymerase is thought to be able to replicate 749 nucleotides per second. By the end of the replication process two new DNA molecules will have been made, each identical to the other and to the original parent molecule.

Such accurate replication is helped by the fact that DNA polymerase has an inbuilt capacity to detect and correct any mistakes it makes in the replication process.

Several families of DNA polymerases have now been identified and new ones are continuing to be discovered. Some of the most useful polymerases for biotechnology are those classified in families labelled A and B. These tend to be single subunit polymerases. Genetic engineering is also adding tailor-made polymerases to the repertoire. Such genetically tailored DNA polymerases have helped increase the speed and accuracy of PCR and enable PCR to be carried out directly from tissue (ie blood). They have also facilitated the development of whole genome amplification and the generation of next generation sequencing tools.

Discovery of RT-PCR

RT-PCR is an extended version of Polymerase Chain Reaction which works in a molecular diagnostic tool that works on the principle of converting the RNA template to a complementary DNA (cDNA) using the reverse transcriptase enzyme.

This cDNA then undergoes exponential amplification using PCR to form multiple copies, which are then used for downstream analysis. Karry Mullis discovered RT-PCR to facilitate RNA detection and quantification. This work won him the Nobel Prize in Chemistry 1993 for introducing this technique and revolutionizing the field of molecular biology.

RT-PCR applications

1.Genome sequencing

2.Detecting changes in gene or chromosomes

3.Characterization of genes

4.The study of gene expressions and mutations

5.RNA virus research

6.Diagnoses of diseases such as leukemia

7.The monitoring of infections.

A tremendous contribution of RT-PCR is seen in the diagnosis of the RNA-virus SARS-CoV-2.

It became the benchmark technology for detection of specific RNA sequences and it was because of this sensitive in vitro method that mass diagnosis of coronavirus became a possibility. For successfully performing PCR & RT-PCR tests the scientists require reagents & laboratory wares that are PCR clean and free from inhibitory agents. Abdos Life Science caters to the needs of molecular biologists by providing PCR clean plastic wares free of DNase /RNase, Pyrogen, Human DNA & ATP.

Abdos PCR products are manufactured using high purity virgin USP Class Vi medical grade polypropylene conforming to US FDA 21 CFR, free from natural rubber and heavy metals too.

Abdos range consists of PCR tubes, PCR Strip tubes, Strip Caps, PCR plates family, sealing silicone mats, sealing polyster films, Aluminium sealing films, Deep well plates family, Reagent reservoir, Square sealing mats, PCR workup racks, PCR workstation rack with lid and PCR work station. Abdos products are available through our distributors in India and 75 countries worldwide. Our Company’s core values are Relationships, Consistency, Aggressive growth, Integrity and Long-term vision.

The Abdos Life Science team truly believe that through these products we have been adding value to the Life Science & Health Care space by improving the lives of people around us.

Source: Abdos Life Science

Author: Bijoy Varma

Head- Marketing & Strategy

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