Premium cotton is distinguished by having extra-long staple fibres e.g. Egyptian, Pima; such cotton also commands a premium price. But as the cotton moves around the world, and through the fabric value chain, there is the potential for it to be diluted with or fraudulently replaced with lower price, lower quality materials.
29 million tons of cotton is grown and sold every year (enough to make 29 t-shirts for every person on earth). Clothing manufacturers like to make quality-related or sourcing claims, but the closer an item gets to wear, the more difficult it is to certify that the garment is really made from the type of cotton they intended.
With DNA testing, there’s nowhere to hide:
Our science partners have developed ways to identify what is real and what is not in this market. They can verify cotton items by identifying the native cotton species via DNA testing. Their methods can tag and test cotton textiles and finished goods using DNA technology to provide a means for traceability to the source were the cotton was grown and harvested. They employ sophisticated DNA testing of the type typically used in human forensics.
Each cotton fibre was originally a living plant cell, and so it had the full complement of cotton genes. By the time the cotton boll has matured, the cells are no longer viable and the DNA begins to degrade, something that continues during the many steps of ginning, spinning, weaving, dying etc. Still, enough DNA fragments remain to allow us to detect important elements of its genetic signature.
They can already tell the difference between something like the premium Pima varieties and common upland cotton also known as fiber typing. A close working relationship with the Agricultural Research Service Genetics Unit of the US Department of Agriculture, enables genetic verification on multiple types of individual cotton cultivars, and assists the cotton industry in protecting quality, traceability, and economic investments.
The USDA scientists have an extensive collection of cotton germplasm from around the world. Like many crops, the cotton has to be adapted to the growing conditions in each region. That means that cotton grown in India, China, Spain, Egypt or Uzbekistan may have unique and detectable differences in their DNA. In the near future a clothing company may be able to make label claims about cotton quality and origins no matter how convoluted the path has been from the farm to the store.
In addition to quality issues, responsible clothing manufacturers like Murray want to be able to avoid sourcing their cotton from parts of the world where undesirable practices like forced child labour are known to happen. This will also protect the farmers who grow the high quality product. There are many other logical applications of this sort of technology such as olive oil, premium wine or the dietary supplement industry.