International collaborative ring trial of four gene-specific loop-mediated isothermal amplification assays in GMO analysis

- First validated gen-specific LAMP assays (bar, pat, cp4-epsps, and Cry1Ac) for GMO screening analysis.
- Specificity, sensitivity, and performance on practical samples test showed good applicability in routine analysis.
- This study supplied the data to standardize these four assays as standards in future.

We performed an international collaborative ring trial to validate gene-specific loop-mediated isothermal amplification (LAMP) assays targeting four exogenous transgenes commonly utilized in the development of genetically modified (GM) crops: bar, pat, cp4-epsps, and Cry1Ac, respectively. A total of 12 laboratories participated in the ring trial and returned their test results. Statistical analysis of the returned results showed high specificity and low limit of detection (LOD) of the four LAMP assays. The LOD for cp4-epsps, Cry1Ac, bar and pat genes assay was 5, 10, 20 and 20 haploid genome equivalents (HGE), respectively. Furthermore, good performance of the four assays was further demonstrated in the analysis of practical samples in which all participating laboratories returned expected and accurate test results. Altogether, the ring trial results confirmed that the four gene-specific LAMP assays can be utilized for quick screening of transgenic traits in routine laboratory analysis.