The difference between internally and externally threaded tubes

Choice of sample storage tube

The choice for the correct sample storage tube for your research purpose can be quite difficult, there is a lot to take into account. In what temperature am I storing the sample, how much volume do I need, what kind of coding options are available and am I using internally or externally threaded tubes? Some scientists make the latter choice based on personal preference, but to make a motivated decision for the most suitable sample storage tube for your research, it is important to know that there are functional differences between an internal thread tube and an external thread tube.

Internally threaded tubes

The internally threaded tube seals from the inside as you can see in the picture on the right. This means that there is no rim on the outside of the tube, allowing for a better fit into storage racks and minimizing tube storage space. The Micronic tube with internal thread features a single turn thread for easy opening and closing of the tube. The internally threaded tube in 96-well format can be sealed off with a Push Cap or a Screw Cap. For effective cryogenic storage a Screw Cap with Silicon O-ring is recommended since it allows for the tightest seal possible. For storage from -80°C and above, either a Push Cap or Screw Cap can be used.

Externally threaded tubes

The externally threaded tube seals from the outside as you can see on the drawing on the right. The Micronic tube with external thread has a triple start thread for optimal sealing quality to ensure long-term sample preservation and storage. Using externally threaded tubes eliminates the possibility of the sample coming into contact with the screw thread, reducing the chance of cross-contamination while improving sample integrity. These sample tubes can also hold a higher (net) volume of material while occupying the same amount of storage space, thus maximizing storage volume. The externally threaded tube in 96-well format can be sealed off with a Push Cap or Screw Cap.

Still undecided?

Still undecided which tube suits your research best? Fill out our tube configurator and find your ideal sample storage tube. Try it out now!