Inter-laboratory validation of visual loop-mediated isothermal amplification assays for GM contents screening

Loop-mediated isothermal amplification (LAMP) has been widely used in many fields of molecular diagnostics, including detection of genetically modified organisms (GMOs). Herein, we report a collaborative ring trial validation of three established visual LAMP assays targeting three common GM elements, namely CaMV35S promoter, FMV35S promoter and NOS terminator, respectively. The high specificity of each assay was confirmed in different GM events analyses, and the sensitivity of each was determined to be 10, 10, and 50 haploid genome equivalents (HGEs) for CaMV35S promoter, FMV35S promoter, and NOS terminator, respectively. The probability of detection was also determined based on specificity and sensitivity data from 10 participating laboratories that returned correct results for the practical sample tests. These results demonstrate that the three visual LAMP assays are sensitive and time-saving, with high application potential for on-spot testing and routine screening of GMOs.