Authors: Xiumin Wang Da Teng Yalin Yang Fang Tian Qingfeng Guan Jianhua Wang
Publish Date: 2011/02/20
Volume: 90, Issue: 2, Pages: 721-731
Abstract
A standard plasmid containing eight targets was developed for quantitative detection of genetically modified GM soybeans and cotton These eight targets were joined in tandem to form the pTLE8 plasmid with a length of 3680 bp This plasmid contains part of the endogenous soybean Lec1 gene the Cauliflower mosaic virus CaMV 35S promoter the Agrobacterium tumefaciens nopaline synthase NOS terminator the PAT gene of the soybean line A270412 the eventspecific 5′junction region of RoundupReady Soya RRS 35SG the Cry1Ac gene from Bacillus thuringiensis Bt the endogenous cotton Sad1 gene and a part of RRS EPSPS gene The PCR efficiencies with pTLE8 as a calibrator ranged from 994 to 1002 for the standard curves of the RRS EPSPS gene and the taxonspecific Lec1 gene R 2 ≥ 0996 The limits of detection and quantification were nine and 15 copies respectively The standard deviation SD and relative standard deviation RSD values of repeatability were from 009 to 052 and from 028 to 211 and those for reproducibility were from 012 to 115 and 042 to 385 respectively The average conversion factor Cf for the CRMs RRS quantification was 091 The RSD of the mean values for known samples ranged from 309 to 1853 and the biases were from 05 to 40 These results show that our method using the pTLE8 plasmid as a reference material RM is reliable and feasible in the identification of GM soybeans thus paving the way for the establishment of identification management systems for various products containing GMO components
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