DNA Stops Counterfeit Cotton
Reputation is everything. A major clothing brand’s reputation hangs on the quality of material, and some want to make sure their suppliers aren’t using child labor. But when a shipment of cotton comes, how does a manufacturer know where it came from? The answer is artificial DNA.
Researchers at City, State-based Applied DNA Sciences are using artificial DNA to tag individual cotton fibers with gene sequences that identify specific suppliers and can’t be duplicated.
The DNA tag is added to the cotton during the ginning process, that is when the seeds are removed and before it gets turned into thread. A machine douses the cotton with a solution containing a unique sequence of DNA molecule derived from plants. While DNA is usually inside living cells, it can also exist in solutions and doesn’t fade or degrade quickly, even after the solution dries.
Applied DNA Sciences CEO James Hayward told DNews that the DNA can’t be removed, even by bleaching, because the DNA-laced solution is absorbed by individual fibers. The DNA even survives getting made into clothing.
Supima, a Phoenix, Ariz.-based non-profit that certifies genuine Pima cotton, a long-fiber variety used by clothing brands such as Brooks Brothers and Land’s End, is promoting the technology among clothiers to make sure that suppliers are really shipping PIma cotton. In the U.K., the Textile Centre of Excellence has been partnering with wool and cotton mills in that country to test their supplies as well.
Since the DNA stays on the fiber, it doesn’t matter what happens to it on the way. So, let’s say Brooks Brothers, which still does the bulk of its manufacturing in the United States, ordered a big batch of cotton fabric, from a Chinese supplier. An employee can take sample and send it to Applied DNA Sciences’ lab to test whether the cotton requested is the same as the one being purchased. If the artificial DNA shows up, and in the right sequence, then that shipment of cotton is indeed the one requested. If it isn’t there, no deal.
As an added bonus, it means there’s a way for clothiers to check if those shirts the guy on the corner is selling are cheap knock-offs. Authorities could use the same technique on a pile of shirts and see if they really are the brand they say they are.
DNA is such a useful marker because it’s made of four components called nucleotides: adenine guanine, cytosine and thymine, the famous A, G, C, and T of the genetic code. In living things A links with G and C links with T, and those pairs, called base pairs, are all in a specific order. To make the DNA tag, scientists break apart the base pairs and rearrange them to make a new sequence. The DNA isn’t alive and it can’t reproduce. But the base pairs form a long, unique string. With enough base pairs it’s possible to have millions of combinations.
And it can’t be copied, since the counterfeiter would have to duplicate the same nucleotide sequence. That’s not possible unless they knew what that sequence was ahead of time.
Applied DNA Sciences got its start tagging industrial electronics that were on their way to U.S. military suppliers. In that case, it was important to be sure that the components in the shipping container really were the ones that the Defense Department contractor ordered, rather than a cheap imitation. They also offer a DNA “fog” that tags criminals. This is an extension of the technology to textiles, but Hayward noted that it can be applied to almost any material.
Credit: Wikimedia Commons / David Nance