Abstract: A microchip digital PCR（dPCR）quantitative method for insect-resistant and herbicide-resistant genetically modified soybean lineMON89788was developed and several critical experimental conditions were studied,including genomic DNA extraction,quality and concentration control of nucleic acid template,screening of the primer probes,PCR program,etc.The reproducibility and quantitative detection limit of the method were also investigated.The quantitative repeatability RSD ranged from 1.17% to 9.97% when a 5% GM soybean（MON89788）sample was analyzed,andall of them met the international requirement that the RSD of transgenic quantitative results should be < 25%. The quantitative results of MON89788samples containing 5%,1% and 0.1% GM were 5.20%,0.94% and 0.11% and the RSD was 6.2%,3.6% and 15.2%,respectively. The limit of quantificationwas 0.1%,which fully satisfiedthe EU’s GM quantitative labeling limit（0.9%）. Applying the method established in this experiment in the quantitative detection of transgenic soybeans may provide strong technical support for standardizing the implementation of transgenic supervision in China.

Key words: genetically modified soybean, digitalPCR, soybean MON89788