Rapid recombinase polymerase amplification-based detection of the bar gene for environmental monitoring of genetically modified soybean and rice

Rapid and reliable methods are required for environmental monitoring of unintended releases of genetically modified (GM) crops. We developed a real-time recombinase polymerase amplification (RPA) assay targeting the bar gene for the rapid detection of GM soybean and rice, combined with a simplified NaOH-based DNA extraction method for field applications. Primer–probe set 4 provided the most specific and reliable detection, while soybean lectin and rice actin served as internal positive controls. Lectin and actin were consistently detected in GM and non-GM samples, respectively. A 0.1 N NaOH extraction method produced DNA of sufficient quality for direct real-time RPA without additional purification. The integrated assay specifically detected the bar gene in GM samples, with no amplification observed in non-GM samples, and generated results within approximately 25 min at 39 °C. This assay provides a rapid, simple, and field-deployable approach for the detection and environmental monitoring of GM soybean and rice.