Current Synthetic and Systems Biology
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Polymerase Chain Reaction and DNA Sequencing: Revolutionizing the Study of Genetics

Zhi Qiang^{* *}Correspondence: Zhi Qiang, Department of Genetics, University of Saskatchewan, Saskatoon, Canada, Email:

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Description

Polymerase chain reaction (PCR) is a powerful laboratory technique that allows scientists to amplify specific DNA sequences. It was developed in the 1980s by Kary Mullis, who was awarded the Nobel Prize in Chemistry in 1993 for his work. PCR makes use of the capacity of the enzyme DNA polymerase to generate a new strand of DNA that is complementary to the template strand. Because DNA polymerase can only add a nucleotide to an already formed 3'-OH group, it requires a primer to which it can add the initial nucleotide. PCR amplifies a specific DNA sequence by repeatedly copying it in vitro (in a test tube) using a DNA polymerase enzyme and specific primers.

Denaturation, annealing, and extension are the three basic processes in PCR. Denaturation involves heating doublestranded DNA to a high temperature in order to separate the two strands. During annealing, short synthetic DNA primers, which are complementary to the target DNA sequence, bind to each strand at a lower temperature. During extension, a DNA polymerase enzyme copies the target DNA sequence by adding new nucleotides to the growing DNA strand.

The process is then repeated in cycles, with each cycle doubling the amount of DNA. This exponential amplification results in a large quantity of the target DNA sequence, which can then be analyzed or manipulated for various purposes. PCR is widely used in molecular biology analysis, genetic testing, and forensics. It can be used to detect the presence of specific pathogens or genetic mutations, as well as to identify individuals based on their DNA profiles. One of the main advantages of the PCR is its sensitivity. It can detect very small amounts of DNA, even a single copy, which makes it a useful tool in many applications, such as identifying infectious diseases or detecting genetic disorders. PCR has also revolutionized the field of DNA sequencing, which is the process of determining the order of nucleotides in a DNA molecule. PCR can be used to amplify specific regions of DNA, which can then be sequenced using various methods.

There are several variations of PCR, each designed for specific purposes. For example, reverse transcription PCR (RT-PCR) is used to amplify RNA sequences, while quantitative PCR (qPCR) is used to quantify the amount of DNA present in a sample.

PCR has also been adapted for use in point-of-care testing, which allows rapid and portable diagnostic testing in remote or resource-limited settings. This has become especially important during the COVID-19 pandemic, where PCR-based tests are used to diagnose the virus.

While PCR is a powerful tool, there are limitations to its use. One limitation is the potential for contamination, which can result in false positives or false negatives. To minimize the risk of contamination, PCR must be performed under sterile conditions, and appropriate controls must be used to ensure accuracy.

PCR is a powerful laboratory technique that allows scientists to amplify specific DNA sequences. It is widely used in molecular biology analysis, genetic testing, forensics, and medical diagnostics. PCR has revolutionized the field of DNA sequencing and has been adapted for use in point-of-care testing. While there are limitations to its use, PCR remains an important tool for many applications.