title: Validation of real-time PCR analyses for line-specific quantitation of genetically modified maize and soybean using new reference molecules.
abstract: Novel analytical methods based on real-time quantitative polymerase chain reactions by use of new reference molecules were validated in interlaboratory studies for the quantitation of genetically modified (GM) maize and soy. More than 13 laboratories from Japan, Korea, and the United States participated in the studies. The interlaboratory studies included 2 separate stages: (1) measurement tests of coefficient values, the ratio of recombinant DNA (r-DNA) sequence, and endogenous DNA sequence in the seeds of GM maize and GM soy; and (2) blind tests with 6 pairs of maize and soy samples, including different levels of GM maize or GM soy. Test results showed that the methods are applicable to the specific quantitation of the 5 lines of GM maize and one line of GM soy. After statistical treatment to remove outliers, the repeatability and reproducibility of these methods at a level of 5.0% were <13.7 and 15.9%, respectively. The quantitation limits of the methods were 0.50% for Bt11, T25, and MON810, and 0.10% for GA21, Event176, and Roundup Ready soy. The results of blind tests showed that the numerical information obtained from these methods will contribute to practical analyses for labeling systems of GM crops.
authors.affiliation: Fundamental Research Laboratory, Asahi Breweries Ltd., Kitasoma-gun, Ibaraki, Japan.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Shindo
authors.forename: Hideo
authors.initials: H
authors.lastname: Kuribara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsuoka
authors.forename: Satoshi
authors.initials: S
authors.lastname: Futo
authors.forename: Chihiro
authors.initials: C
authors.lastname: Sawada
authors.forename: Jinji
authors.initials: J
authors.lastname: Shono
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Akiyama
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Goda
authors.forename: Masatake
authors.initials: M
authors.lastname: Toyoda
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hino
mesh_terms: D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D012015:Reference Standards; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013025:Glycine max / Q000737:chemistry / Q000235:genetics*; D003313:Zea mays / Q000737:chemistry / Q000235:genetics*
chemical_list: D018744:DNA, Plant