Not all liquid sample tubes are created equal, and there are a lot of options on the market. In this article, we explore what your lab should consider when purchasing liquid sample handling tubes for DNA/RNA extraction.

Organization and the right equipment are key to the success of any DNA/RNA extraction project. Your lab must be able to ensure each sample is fully accounted for from storage to extraction to transportation. Even one failed sample can lead to wasted time recollecting and rerunning samples.

That’s why the tubes those samples are stored in are so critical. While there are plenty of tubes on the market, there are certain features that make storage and organization easier and ensure the integrity of your samples is preserved throughout the entire DNA/RNA extraction process.

To find the right tubes, you need to know what to look for. Here are the top four features to consider when choosing new sample storage tubes.

4 Key Considerations for Finding the Right Sample Tubes

#1. Tube and Rack Construction Quality

The first thing to look at is the tube construction itself. It should be made of a material that is both durable and resistant to leaching material into your sample. Polypropylene and polyethylene are ideal choices here.

You also want to make sure that the tube can withstand the pressures of transportation and being run through automated protocols. Especially if your samples are going to be shipped to other sites, finding tubes that are leak-proof and able to withstand harsh travel conditions should be a top priority for your lab.

In addition to durability, finding racks and tubes with value-added construction features is always a plus. Look for features like:

  • Easy locking systems: There are racks with convenient locking systems that keep lids on the rack and allow them to stack on top of each other easily and securely.
  • External threading: Tubes with internal threads can trap critical sample in the threads. Additionally, external threads allow for a smaller tube construction without reducing working volume.
  • Tube centering and protection: Look for racks with curved well walls and tube centering features that ensure your tubes are safe during any automated workflows.

#2. Barcode Type and Placement

Another key consideration is the coding of the tube. How many codes are there on the tube? What formats are those codes in? Can they be read manually, by a barcode scanner, or a full rack scanner?

Ideally, you will want a tube with multiple code options. If possible, find tubes that are tri-coded. This means they have a human-readable code, a 1D barcode and a 2D code, all on the same tube, so no matter what process your lab has in place, you have a way to read that sample tube.

Also, make sure those codes can’t be easily removed. This goes back to the construction of the tube. Some may require you to place barcode stickers on the tube, while other have laser-etched coded that won’t wear off or scratch easily over time.

#3. Rack Storage Space Requirements

Storage space can be an easy feature to overlook. But did you know that storage space directly ties to your lab’s energy costs?

If you’re using space-inefficient tubes and SBS racks, then you’re taking up more valuable freezer space in cold storage than you need to be. Especially if your lab is using conventional cryoboxes to store samples. In many cases, these cryoboxes are designed for volumes of 1-2ml. However, for many DNA/RNA extraction applications, 500 μl or 300 μl sample volumes are more than sufficient.

Therefore, rack construction matters. Find a provider that sizes their racks based on tube height and working volume. In many cases, this can lead to using 40-80% less freezer space to store your samples. Now extend those space savings across multiple freezers, and you begin to use less freezers. Less freezers means reduced energy costs and a reduced carbon footprint.

#4. Compatibility with Automation and Downstream Applications

It’s important to double check that the tubes you go with are compatible with any automation or downstream application your samples will be run through.

Look for the Society for Biomolecular Screening (SBS) format. This form factor is the standard that many automated systems use to ensure your samples can be used interchangeably with any equipment and automated instrumentation you already have in your lab.


While liquid sample tubes may seem simple or one-dimensional, there are plenty of features and qualities to consider that can have a major effect on your DNA/RNA extraction capabilities. It’s important to find a tube and rack design that can withstand the rigors of storage, transportation and automation. It’s equally important to consider the build quality and space saving features.

At AutoGen, we’ve taken the time to consider all these factors to provide a tube and rack design perfect for DNA/RNA extraction automation. We call them the STAR 2D Tri-coded Tubes, and we believe you won’t find a better sample tube on the market.

If you’re interested in getting these tubes into your workflows, get in touch. Our team is here to help your lab become more efficient.