1 research outputs found
Development and Interlaboratory Validation of a Simple Screening Method for Genetically Modified Maize Using a ΔΔ<i>C</i><sub>q</sub>‑Based Multiplex Real-Time PCR Assay
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 (<i>C</i><sub>f</sub>) value. We developed a simple screening method
that avoids the need for a calibration curve and <i>C</i><sub>f</sub> value. In this method, Δ<i>C</i><sub>q</sub> values between the target sequences and the endogenous gene
are calculated using multiplex real-time PCR, and the ΔΔ<i>C</i><sub>q</sub> 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