Development of Certified Matrix-Based Reference Material as a Calibrator for Genetically Modified Rice G6H1 Analysis

Abstract

The accurate monitoring and quantification of genetically modified organisms (GMOs) are key points for the implementation of labeling regulations, and a certified reference material (CRM) acts as the scaleplate for quantifying the GM contents of foods/feeds and evaluating a GMO analytical method or equipment. Herein we developed a series of CRMs for transgenic rice event G6H1, which possesses insect-resistant and herbicide-tolerant traits. Three G6H1 CRMs were produced by mixing seed powders obtained from homozygous G6H1 and its recipient cultivar Xiushui 110 at mass ratios of 49.825%, 9.967%, and 4.986%. The between-bottle homogeneity and within-bottle homogeneity were thoroughly evaluated with consistent results. The potential DNA degradation in transportation and shelf life were evaluated with an expiration period of at least 12 months. The property values of three CRMs (G6H1a, G6H1b, G6H1c) were given as (49.825 ± 0.448) g/kg, (9.967 ± 1.757) g/kg, and (4.986 ± 1.274 g/kg based on mass fraction ratio, respectively. Furthermore, the three CRMs were characterized with values of (5.01 ± 0.08)%, (1.06 ± 0.22)%, and (0.53 ± 0.11)% based on the copy number ratio using the droplet digital PCR method. All results confirmed that the produced G6H1 matrix-based CRMs are of high quality with precise characterization values and can be used as calibrators in GM rice G6H1 inspection and monitoring and in evaluating new analytical methods or devices targeting the G6H1 event.

Development of a Duck Genomic Reference Material by Digital PCR Platforms for the Detection of Meat Adulteration

“…RM and CRM are the quality assurance of testing data, which can evaluate the measurement method and monitor the measurement process. DNA CRMs originated from the detection of genetically modified ingredients because quantitative testing is needed in this field [15]. Subsequently, a large number of molecular diagnostic standards have been developed in the field of medical testing.…”

“…Certified reference materials (CRMs) are reference materials (RMs) characterized using a metrologically valid procedure for one or more specified properties, accompanied by an RM certificate [14], which can be used for calibration of a measurement system, assessment of a measurement procedure, for assigning values to other materials, and quality control. Several DNA-based CRMs have been developed, such as for genetically modified organisms [15][16][17], cancer diagnosis [18][19][20], foodborne pathogens [21], and forensic science [22,23].…”

Digital PCR-Based Characterization of a g10evo-epsps Gene-Specific Matrix Reference Material for Its Food and Feed Detection

“…Each has advantages and disadvantages under the conditions of development, valuation, storage and transportation. The preparation of matrix RMs is complex [15][16][17], but powder is stable in storage and easy to transport. Preparation of gDNA RMs is straightforward and easily quantified, but specific storage and transportation conditions are required [18,19].…”

Collaborative Ring Trial of the Applicability of a Reference Plasmid DNA Calibrant in the Quantitative Analysis of GM Maize Event MON810

“…During quantitative qPCR analysis of GM contents, reference materials (RM) are necessary for maintaining the accuracy of laboratory measurements over time and inter-laboratory comparability of quantitative results [ 11 , 12 ]. Currently, various types (such as matrix-based, plasmid-DNA-based, genomic-DNA-based, and seed-based) of RMs have been developed for GMO detection in the EU, USA, Japan, and China [ 11 , 12 ]. At present, over 200 CRMs have been developed, containing 22 genomic-DNA-based CRMs, 188 matrix-based CRMs, and 9 plasmid-DNA-based CRMs [ 12 ].…”

“…This number of developed CRMs remains far less compared with the large number of commercialized GM crop events (more than 400), reflecting the reality that more CRMs need to be developed quickly [ 12 , 13 ]. Matrix-based CRMs remain the most widely used because they present similar properties to real samples and are easily traceable to the International System of Units (SI) of the gram [ 11 , 14 ]. The disadvantages of matrix-based CRMs in GMO quantitative analysis include the narrow dynamic range of quantification, multiple and complex preparation procedures, high cost, and difficulty in obtaining the homogeneous candidate [ 15 , 16 ].…”