title: Development and Interlaboratory Validation of a Simple Screening Method for Genetically Modified Maize Using a ΔΔC(q)-Based Multiplex Real-Time PCR Assay.
abstract: A number of genetically modified (GM) maize events have been developed and approved worldwide for commercial cultivation. A screening method is needed to monitor GM maize approved for commercialization in countries that mandate the labeling of foods containing a specified threshold level of GM crops. In Japan, a screening method has been implemented to monitor approved GM maize since 2001. However, the screening method currently used in Japan is time-consuming and requires generation of a calibration curve and experimental conversion factor (C(f)) value. We developed a simple screening method that avoids the need for a calibration curve and C(f) value. In this method, ΔC(q) values between the target sequences and the endogenous gene are calculated using multiplex real-time PCR, and the ΔΔC(q) value between the analytical and control samples is used as the criterion for determining analytical samples in which the GM organism content is below the threshold level for labeling of GM crops. An interlaboratory study indicated that the method is applicable independently with at least two models of PCR instruments used in this study.
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Noguchi
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Kozue
authors.initials: K
authors.lastname: Sakata
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Sato-Fukuda
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Ishigaki
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization , 2-1-12 Kannondai, Tsukuba 305-8642, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Mano
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization , 2-1-12 Kannondai, Tsukuba 305-8642, Japan.
authors.forename: Reona
authors.initials: R
authors.lastname: Takabatake
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization , 2-1-12 Kannondai, Tsukuba 305-8642, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kitta
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Teshima
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Kondo
authors.affiliation: National Institute of Health Sciences , 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nishimaki-Mogami
mesh_terms: D002138:Calibration; D018744:DNA, Plant / Q000032:analysis* / Q000235:genetics*; D030841:Food, Genetically Modified; D007564:Japan; D030821:Plants, Genetically Modified / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D003313:Zea mays / Q000235:genetics*
chemical_list: D018744:DNA, Plant