PCR tubes are plastic tubing that is designed specifically for use in the Polymerase Chain Reaction, a procedure that converts an initial sample of DNA into many millions of copies in a very short time. Designed to fit well into the thermal cycler that is used in the process, PCR tubes are available in a variety of sizes, shapes, and colors. It is important to select a tube that is compatible with the thermal cycler in order to get the best results.

Generally, PCR tubes are made from polypropylene, which is chemically inert and can withstand rapid temperature changes during thermal cycling. The tubing is also typically manufactured to be thin and uniform in thickness in order to optimize heat transfer. In addition, a wide range of cap shapes and styles are available, including flat caps, dome-shaped caps, and specialized rims that prevent evaporation during the reaction. Several other features have been developed to make the tubes easier to work with.

In addition to the aforementioned features, a wide range of different color options are available to suit various experiments and applications. Clear tubes are ideal for standard PCR, while white tubes prevent fluorescence from refracting and diffusing around the tube wall, which increases real-time qPCR sensitivity. Moreover, PCR tubes can be customized with a label that is printed or written on. This makes it easy to track the contents of each tube and to distinguish them from one another.

The cap on a PCR tube is an important part of the overall design of the tubing, and it must be carefully selected to ensure that the tube can be sealed properly and securely. Generally, the cap will be either dome-shaped or a flat-topped style, with both types being available in a variety of heights. A lower-height cap is often recommended for a PCR tube, as it reduces the amount of space in the reaction and helps to avoid sample evaporation during the heating and cooling process.

PCR tubes are made under strict conditions in order to meet quality standards, and they must pass a number of inspections and tests before they can be sold. These tests include ensuring that the tubes are free of DNA, RNase, endotoxin, and other contaminants. The tubes are also typically gamma irradiated, which is an additional step that can help to ensure the safety of the samples inside. The resulting product is then packaged and sealed under automated machinery, which further protects the tubes from contamination and evaporation. The result is a high-quality tube that can be used in a variety of molecular biology biochemistry applications.