The volume of a tube can be expressed in several ways by the manufacturer. You may see terms such as “nominal volume”, “working volume” or “storage volume” used in the tube’s description. What is key to you as the end user is understanding the volume a tube will hold and still be fit for purpose. If the volume of the tube is incorrectly over exceeded, then this can lead to damage for both the tube and the sample.
But what the tube is called in its description may not be an accurate indication of what volume the tube will hold and, for example, be safe to freeze at. We also must consider the cap used on the tube, the accuracy of the dispensing method, burst pressure and thawing conditions.
A key consideration when choosing the correct tube is the makeup of the sample you are storing and how you will be storing. Samples with a high-water content, including biological samples, are an exception to the rule. Most liquids lose volume as they freeze however water forms a crystalline solid that takes up more space that the liquid itself does. The largest expansion of water occurs at the 0oC or slightly lower. This fact needs to be accounted for when selecting the correct tube size for your sample size so as not to over fill the tube.
This is not all we need to consider when selecting the correct tube size for biological samples. As the sample freezes the amount of pressure within the tube increases* and can lead to the tube cracking, or lids popping off. At AltemisLab we have calculated the safest maximum working volume for our range of AlteTubes and this volume can be found on the spec page for each tube. To ensure that both your sample and the tube stay safe please do not exceed the stated maximum working volume.
At AltemisLab, we prioritize finding the ideal tube size for your workflow. That’s why we offer to send samples of tubes or racks for testing in your own environment. Additionally, our team is available to visit your lab to provide assistance and answer any questions you may have. Your satisfaction is our top priority.