Development of a Rapid Event-Specific Loop-Mediated Isothermal Amplification Detection Method for Genetically Modified Maize NK603

Development and evaluation of a novel loop mediated isothermal amplification coupled with TaqMan probe assay for detection of genetically modified organism with NOS terminator

In this study, we aim to develop a novel loop mediated isothermal amplification (LAMP) coupled with TaqMan (LAMP-TaqMan) method for quick qualitative detection of genetically modified organism (GMOs). We designed four LAMP primers and one TaqMan probe for the LAMP-TaqMan detection method to detect the nopaline synthase gene (NOS) terminator in GMOs. This assay enabled the amplification of DNA within ~20 min at a constant temperature of 65 °C. This assay detected as few as five copies of target sequences, which had a high specificity similar to the TaqMan qPCR method. Furthermore, the LAMP-TaqMan detection method was successfully used to amplify and detect DNA from food samples of the major crops (soybean, maize, rice, etc.). In summary, a novel LAMP-TaqMan assay has been developed, which has the similar sensitivity but takes less time than the TaqMan qPCR method. This method offers a novel approach for rapid detection of GMOs in foods.

Detection of Bar Transgenic Sugarcane with a Rapid and Visual Loop-Mediated Isothermal Amplification Assay

Genetic engineering offers an attractive alternative in sugarcane breeding for increasing cane and sugar yields as well as disease and insect resistance. Bar transgenic sugarcane employing the herbicide tolerance is a useful agronomical trait in weed control. In this study, a loop-mediated isothermal amplification (LAMP) assay for rapid detection of the bar gene in transgenic sugarcane has been developed and evaluated. A set of six primers was designed for LAMP-based amplification of the bar gene. The LAMP reaction conditions were optimized as follows: 5.25 mM of Mg(2+), 6:1 ratio of inner vs. outer primer, and 6.0 U of Bst DNA polymerase in a reaction volume of 25.0 μL. The detection limit of the recombinant plasmid 1Ac0229 was as low as 10 copies in the developed LAMP, which was 10-fold higher sensitive than that of conventional PCR. In 100 putative transgenic lines, the bar gene was detected in 100/100 cases (100%) by LAMP and 97/100 cases (97%) by conventional PCR, respectively. In conclusion, the developed LAMP assay is visual, rapid, sensitive, reliable, and cost-effective for detection of the bar specific transgenic sugarcane.