The polymerase chain reaction (PCR) method was first developed in 1983 by Kary Mullis, an American biochemist. It enabled scientists and researchers to duplicate complete or partial copies of a specific segment of DNA. It also helped scientists amplify a particular segment of DNA, allowing them to study in detail.
This process is performed using a thermal cycler, also known as a PCR machine, thermocycler, or DNA amplifier. A thermal cycler is designed with a thermal block. It features holes that hold the PCR reaction mixtures. The device is used to raise and lower the temperature of the block in pre-programmed, discrete cycles.
This process has been implemented in laboratories across the world and has dramatically impacted the kind of scientific research that can be performed today – even how we have researched COVID-19. It’s a true example of how the discovery of new technology impacts our everyday lives. Learn more about PCR tubes and their importance below.
What Is A PCR Tube?
A PCR tube or vial is a laboratory apparatus where a reaction mixture is placed before it goes into a thermal cycler.
What Are PCR Tubes Designed For?
PCR tubes are used for transfer applications. They are also utilized for DNA extraction protocols, molecular biology applications, reverse transcriptions, and qPCR.
One application that takes advantage of a PCR is the COVID-19 test. Health providers extract tissue samples from the nasal cavity to identify the presence of SARS-CoV-2 (virus genetic material). After the samples go into the thermal cycler, millions of copies of the SARS-CoV-2 appear in the tube. These are then tested further to determine a positive or negative outcome.
What is Unique About the PCR Tubes?
Made from medical-grade polypropylene, these durable, quality tubes allow scientists to conduct several tests for optimum results. In addition, these tubes are free from DNase, RNase, PCR, and DNA inhibitors, ensuring reliable, reproducible outcomes.
PCR tubes have several features such as conical bottoms for stability in centrifugal machines, which are used heavily in modern research laboratories. To keep track of samples easily, they have frosted strips intended for labeling. They have caps that click into place, providing tight sealing to keep evaporation at bay.
PCR tubes size varies—they are available in 0.2 ml and 0.5 ml capacities. The restricted volume of the tubes curbs the use of costly reagents. These tubes have thin walls that enhance heat transfer between the thermal block and mixture. Once placed in a thermal cycler, the tubes ensure efficient and quick, uniform heating and cooling during a PCR.
The tubes have a smooth body that eliminates gloves from snagging and provides an easy grip while handling test samples. Moreover, since they’re autoclavable, the tubes can be placed in a pressure cooker or laboratory autoclave to be sterilized for reuse.
Some manufacturers like Greiner Bio-One provide PCR tube strips in different colors for easy identification.
How to PCR Tubes Are Handled
Until the tubes are ready to be used, they must be kept sealed in the original packaging. Once opened, follow protocols that include:
- Keep track of samples by ensuring they’re labeled with a fine permanent marker.
- To avoid contaminating the bags that the tubes come in, shake them onto an open gloved palm or clean surface.
- Tubes that are in use should be neatly organized in an appropriately sized rack.
- Tubes that carry samples such as PCR products for downstream applications or DNA extracts can be stored in a tube box or labeled airtight pouch.
How PCR Tubes Are Stored
To avoid contamination, tubes should be kept at room temperature and stored away from dampness, dust, or PCR products. Furthermore, once removed, unused tubes should not be returned to their original packaging.
Though it may seem like a minor invention only relevant to the scientists that use them every day, PCR tubes have actually had a massive influence on the kinds of research we are able to carry out today. They continue to prove that every invention has its place in our modern world and that companies at the forefront of these discoveries hold the key to new growth in our ever-adapting world.