The Covid-19 pandemic has been sprawling news headlines for nearly 2 and a half years. A result, the idea of PCR testing has been widely spread as well. PCR testing is likely a familiar term to most, however, not many know the process behind it or the applications it has in gene cloning research.
What is PCR and How Does It Work?
PCR, or polymerase chain reaction, is a process used to make copies of small segments of DNA. The technique allows researchers to amplify the DNA template provided in order to analyze the sequence. Every PCR operation relies on five major components: a DNA template, Primers, DNA nucleotide bases, an enzyme called Taq polymerase, and a buffer solution. These components interact during three different stages that begin with the denaturation of the template DNA into two strands, allowing the primers to attach to the template strands, and ending with the extension of new DNA with Taq Polymerase. These three stages seen below are repeated 20-40 times over the course of a few hours before the DNA fragments are analyzed using methods such as electrophoresis. For more information on the basics of PCR check out this article by Khan Academy here. It gives a great overview of the overall process
Current Uses of PCR
Overtime, PCR has undergone changes in order to both streamline and enhance its functionality. As technology progresses, PCR interfaces have become more advanced. The use of microfluidic systems has created a new subcategory of devices that tackle issues such as portability and cost effectiveness.
PCR In Microfluidic Platforms:
A microfluidic platform utilizes a microchip that can move or analyze small amounts of fluid. These chips are made of thermoplastics which include materials like acrylic, glass, silicone or a substance called PDMS (transparent silicon rubber). This system works through a pump that can move fluid into the chip at a fixed rate. Channels within the chip can then process the liquid through performing chemical and or physical reactions. In addition to this, cells, nanoparticles or other small particles are also processed. The use of these microfluidic chips allows for manufactures to create smaller, more cost efficient devices, and in this case PCR testing that can be accessible to the general public than before.
The Future of PCR
PCR technology is set to play a pivotal role in molecular diagnostics. With the use of microfluidic chips, the PCR technique is destined to be more affordable and compact. These devices are also on track to use Reverse Transcriptase PCR analysis of immunomagnetic exosomal RNA. A study published by Nature Communications proves this through their ability to use a microfluidic chip to analyze mRNA and its relation to drug resistance. Using this information the research proves enzyme mRNA levels have a correlation with levels found in parental cells. More about the study can be found here. This is just the brink of the sampling and analysis capabilities of future PCR applications. With these advances in technology and accessibility, research utilizing PCR will have a significant impact in future DNA/RNA sequencing.