The Importance of Choosing the Right Sterile Swabs for DNA Collection
DNA is a molecule found in humans and virtually every other living thing on the planet. Through this hereditary material, testing companies can discover a world of information about any given individual. Virtually all cells in the body carry the same DNA, but the cheek is often used as the primary site for collecting DNA.
Swabbing the cheek is an approach widely used across a number of applications, including paternity testing, criminal investigations, and determining ancestry. This method is preferred because it’s non-invasive, unlike blood tests. (As you might imagine, it’s a welcome alternative for needle-averse individuals!) The cheek is also an ideal site for testable genetic material, as a wealth of DNA can be retrieved from just a small sample of saliva.
That said, there are some considerations to be mindful of when it comes to using cheek swabbing to extract DNA. Most importantly, you need to have the right tools.
You might think that all swabs are created equal, but that’s not the case when it comes to DNA testing. It turns out these little swabs play a major role in achieving accurate DNA results. In fact, a study published by the Journal of Forensic Research confirmed that the tightness of cotton found on sterile swabs can actually impact the odds of creating conclusive DNA profiles.
Thus, if your situation is critically important – for instance, you’re ruling out a suspect in a homicide case – there’s absolutely no room for mistakes!
So, choosing the right sterile swabs is a critical component in ensuring accurate DNA results. But can’t you just use the regular cotton swabs found at the grocery store to retrieve DNA?
In theory, you could but the results would be less than perfect. The swab is likely to return inconclusive results. At a minimum when you’re collecting a DNA sample the swab should be sterile.
This eliminates contaminants that may cloud your results. Optimally, you should use a DNA Free swab that is tested and certified to be DNA free.
When it comes to selecting the right sterile swab, you have some choices. While they all serve the same purpose, swabs can be made from different materials. We’ll explore each below, along with its properties and pros and cons.
Foam Sterile Swabs
Foam-tip sterile swabs, as their names suggest, have foam ends designed to capture the cells found inside a person’s cheek (also known as buccal cells). The foam is highly absorbent, which is ideal for collecting and retaining saliva. Since they’re non-abrasive, they won’t cause any discomfort to the DNA donor.
Their gentle tip also makes it easy for nurses and medical professionals to rub the swab thoroughly in the cheek pocket and near the gum line, where saliva often accumulates.
Among all the types of sterile swabs, foam tip swabs have the highest particle collection capacity. Their porous nature allows them to capture a high-quality DNA sample, and the retrieval process is equally efficient. When lab workers need to release the sample, all they’ll have to do is elute the foam tip into their preferred buffer method.
Foam tip swabs are also available in a variety of different sizes to accommodate all types of donors and applications. Small and regular tip sizes available, and the tip also comes in different shapes, including standard, rectangular, and round.
You can also choose among different shaft materials, including plastic and polypropylene. To preserve sterility, each swab is individually wrapped.
Flocked Sterile Swabs
Like foam tip swabs, flocked sterile swabs have superior collection and release characteristics. Although they aren’t as absorbent as the foam tip swabs, they feature unique flocked fibers which make collection and elution simple and effective.
Polyester flock swabs are commonly used in buccal cell collection, and due to their excellent absorption and elution capabilities, they are the go-to options for rapid diagnostic testing.
Flocking refers to a process of applying short fibers to an adhesive-coated surface, resulting in a swab with a velvet-like brush tip.
Their flocked fiber tip structure also makes them a gentler alternative to foam and cotton sterile swabs. Thus, they can be used even in newborns, and their collection characteristics make it possible to collect saliva even in children whose salivary glands may not be developed.
These, too, come in a variety of options. Tip sizes range from mini (18.4 by 3.4 mm) to large (16.2 by 5.3 mm) to even elongated (17.3 by 5.5 mm). Flocked sterile swabs are also pre-packaged to prevent contamination.
Cotton Sterile Swabs
Finally, there’s the swab everyone knows and loves: the cotton swab. Again, these medical-grade cotton sterile swabs are far different from those you use at home.
Not only do they feature longer shafts for convenient cell collection, they also may be produced in cleanroom environments to prevent any possibility of DNA contamination.
By nature, cotton is a bit more abrasive than the foam and flocked swabs described above. Yet, that can be an advantage for DNA collection – it provides ample friction for releasing buccal cells. It’s also still gentle enough to prevent any discomfort.
Cotton sterile swabs are also versatile because you can either elute the swab in a buffer or remove the tip and drop it into a vial. Like the varieties described above, cotton sterile swabs are available in a variety of sizes and quantities, and are packaged individually.
Choosing the Right Sterile Swab
Now that you’re familiar with the different swab options available for DNA collection, which will you choose? Here are some factors to consider before making your decision:
- Do you need an ample DNA size for your application, or will it suffice to have a small sample?
- How old are the donors from whom you’re collecting DNA?
- Will a professional be collecting the DNA, or will the donor themselves be performing the retrieval?
- Is the sterile swab going to be part of a kit?
- Will the samples be transported, or will the tests be performed on premises?
No matter your unique needs, Harmony Lab & Safety Supplies has the right sterile swabs available for your DNA/buccal cell retrieval purposes. With dozens of materials, sizes, shapes, and quantities to choose from, we have a diverse selection of low-cost swabs available.
All of the options listed above are available at HarmonyCR.com, where you can view each swab’s specific properties to make the best selection for your business.
If you’re still unsure on which swab is perfect for you, give our supply specialist a call and they’ll be glad to help you choose the right swab for your needs.