The world of science and medicine never stops evolving. Every day, new technologies emerge and improve to give scientists more tools and methods to work with. Each innovation creates new and exciting potential across a wide range of fields and markets. One cutting-edge method that many industries are closely watching is the polymerase chain reaction. Polymerase chain reaction technology allows scientists to copy and amplify DNA samples for more accessible study quickly. How exactly does this technology work? What does it mean for various fields of science and medicine? Explore the technology and potential of this field with this guide on the advantages of polymerase chain reaction in diagnostics and beyond.

An Introduction to the Polymerase Chain Reaction Technique

In 1983, biochemist Kary Mullis discovered the polymerase chain reaction technique, and this accomplishment forever changed the world of DNA studies. The polymerase chain reaction method presented a faster and simpler way to study DNA, and scientists can focus on any DNA sample they want and amplify it exponentially. PCR has since become fundamental in various scientific and medical fields, including genetic testing, criminal forensics, medical research, analysis of ancient DNA, and more. Mullis even shared the Nobel Prize in Chemistry in 1993 for his discovery of the technique.

How Polymerase Chain Reaction Works

Despite its incredible usefulness and potential, the polymerase chain reaction technique is relatively simple. Scientists can perform PCR with many different types of DNA samples, and these samples come from tissues or organisms such as blood, skin, saliva, hair, or microbes. Because PCR is such a sensitive assay, scientists only need trace amounts of DNA to perform the procedure.

Within its PCR assay are the template DNA, the polymerase DNA, primers, and nucleotides. These components work together to create the PCR product. During the PCR process, the DNA’s double helix separates. The primers bind to complementary sequences of DNA, creating templates out of the two DNA strands. The DNA polymerase then uses these templates to assemble a new DNA strand out of the freestanding nucleotides. As PCR goes on, these new DNA strands become templates themselves. The replication continues, exponentially amplifying the sample.

Once the PCR product is complete, scientists must be able to visualize the DNA to analyze it. They can achieve this through techniques like staining the DNA or labeling primers and nucleotides with fluorescent dyes. Scientists might also use agarose gel electrophoresis, which separates DNA products by size and charge. These visualizing methods help scientists understand the PCR product as they study it, allowing for more precise insights.

Quantitative PCR

While polymerase chain reaction technology is instrumental in its simplest form, scientists have developed various adaptations of the technique to specialize in certain areas. One such adaptation is a quantitative polymerase chain reaction, which creates Quantitative PCR (qPCR) or Real-Time PCR. This method allows scientists to examine the amount of a given sequence within a sample. For example, qPCR will enable researchers to detect RNA viruses—like HIV—and amplify these specific sequences until there’s enough of a sample to measure and study. With this technique, scientists can study the levels of a specific condition or genetic mutation within various cell populations, which offers insight into where these conditions show up and affect the body.

Applications of Polymerase Chain Reaction

Several fields within science and medicine make use of polymerase chain reaction technology. Some scientists use this technique to clone DNA for sequencing, gene cloning, and gene manipulation. Others amplify ancient samples of DNA for further study and analysis. Forensic scientists also make use of PCR methods, often by analyzing genetic fingerprints for DNA profiling. This same technique is also helpful in parentage testing. However, one of the most promising fields that can benefit from PCR is medical diagnostics.

Polymerase Chain Reaction in Diagnostics

Polymerase chain reaction technology holds incredible potential for the field of diagnostics, and its uses continue to grow. Genetic testing and diagnosis are a massive part of this, and PCR techniques allow scientists to test parents or children for genetic diseases and their effects. Doctors can also take this further by obtaining prenatal DNA samples and testing developing embryos for diseases and conditions. This can help both doctors and parents prepare a fetus and expectant mother for any complications during pregnancy.

PCR technology also benefits the field of cancer research. Doctors can use PCR-based testing to obtain an early diagnosis of malignant diseases like leukemia and lymphomas. These tests also allow doctors to study mutations resulting from certain forms of cancer. These diagnostic improvements allow for earlier treatments, which are far more successful than treating cancer in later stages.

In addition to studying genetics, PCR technology also gives insight into infectious diseases. One extremely relevant example of this is the use of PCR-based testing against the SARS-CoV-2 viral genome. Scientists have used PCR techniques to sequence and analyze the viral genome. Meanwhile, the high sensitivity of PCR-based COVID-19 testing allows health professionals to detect the virus soon after infection. PCR tests can detect the presence of COVID-19 even before a patient starts to show symptoms. Fast and reliable testing is an invaluable part of monitoring the disease, starting treatment, and preventing the further spread of the virus.

Advantages of PCR in the Field of Diagnostics

Why is PCR technology so invaluable for diagnostics? One of the most significant advantages of polymerase chain reaction in diagnostics is its speed. Because PCR technology creates replicas, it can deliver results in a fraction of the time that culturing and other methods require.

Beyond the incredible speed of this method, PCR techniques are helpful when detecting pathogens that require a long cultivation process or struggle to grow in vitro. Even better, PCR technology requires less genetic material than other tests, making testing more accessible in these scenarios.

Limitations of PCR in the Field of Diagnostics

Despite its advantages, PCR technology also has its limitations. PCR techniques don’t work in every situation. Before testing, scientists must have information about the DNA sequence to ensure that the DNA polymerase binds appropriately to the template. Furthermore, the DNA polymerase can create mistakes like all enzymes, such as false mutations in the PCR product. Additionally, the specificity of PCR technology means that even trace amounts of contamination will amplify with the DNA, creating incorrect or misleading results.

Polymerase chain reaction technology continues to evolve as an indispensable tool in diagnostics and beyond. Here at Gener8, we work with companies to produce a breakthrough in vitro diagnostic medical devices that aid in PCR techniques and other crucial applications. Push the boundaries and bring your device design to life when you work with the highly passionate and highly qualified teams at Gener8.