Organic cotton prohibits genetically modified seeds, chemical pesticides and fertilizers. Still, genetic modifications are often found in products sold with organic labels.
Hohenstein is one of the few testing labs accredited to ISO 17025 for the ISO/IWA 32:2019 protocol. For example, this means we provide evidence of non-GMO cotton to meet certification requirements of the international Global Organic Textile Standard (GOTS).
We were also one of the first labs able to identify and quantify GMOs. We identify known genetic modifications in the (raw cotton) sample and quantify their respective proportions.
- Quality control/comparison
- Product identification
- Fraud management
- Supply chain transparency
- Organic cotton certification
- Marketing claim verification
Our GMO screening provides a clear yes/no statement about the presence of genetically modified cotton in the tested sample. For ISO/IWA 32:2019 and GOTS, testing must be performed on raw cotton or chemically untreated yarns and textile surfaces.
- The sample is shredded and the cotton fibers are mechanically and enzymatically extracted. The genetic material (DNA) is separated from the fibers and purified through a multi-stage process.
- If the DNA contains a specific target sequence (gene marker), genetic modification is indicated and molecular biological evidence is obtained. Control reactions are used to detect unmodified cotton DNA and exclude false-negative results.
The DNA is generally protected in the nucleus of the cotton fiber. In rare cases, DNA analysis does not work. For example, the cotton can be so stressed during processing that the DNA in the cell nucleus has been damaged or destroyed. In this case, we recommend taking samples from previous process stages or testing the raw material directly.
Identification and quantification of GMOs distinguishes between their presence due to minor contamination versus an admixture in larger proportions, helping manufacturers, brands and retailers with supply chain and fraud management.
Upon request following a positive GMO screening, further DNA analysis can specifically search for different cotton lines with known genetic modifications. We quantify the respective proportion within the sample.