Genetically Modified Soya Research Articles

Analysis of genetically modified soya and soya products using a fluorescence probe based on PCR-initiated isothermal amplification of G-quadruplex DNA

We proposed a novel strategy for the analysis of genetically modified (GM) soya samples by combining PCR-initiated generation and isothermal amplification of G-quadruplex DNA. PCR primers were designed to consist of a target-specific sequence, a G-quadruplex complement sequence, and a nicking endonuclease recognition site. After the PCR step, the nicking enzyme cut the recognition site, and single stranded G-quadruplex sequences were displaced and further amplified by polymerase during the isothermal amplification reaction. Then, the G-quadruplex sequences combined with N-methyl mesoporphyrin IX to generate strong fluorescence. This method has a detection limit of 0.2% and a linear range from 50% to 0.5% GM content. When exponential isothermal amplification was coupled to the preceding amplification step, the detection limit was further improved to 0.02% GM soya. GM contents were successfully detected at 0.1% GM percentage in soy milk and 0.9% GM percentage in tofu and dried tofu samples. The method may be applied to the analysis of various GM species simply by changing the target sequence in the primers.

A necessity of introduction of the system of registration of GMO is for Ukraine

The article presents the main methodological approaches and criteria for the necessity of development and introduction of the State Registration of GMOs sources in Ukraine. The list of analytical researches that are to be carried out at the registration of the GMO source, expert evaluation of GMO identification methods, reproduction of detection methods, identification and quantification of GMOs are given. Submitted and analyzed legislative documents regulating the procedure for registration and control of GMO circulation in the countries of the European Union and Ukraine. DNDKI of veterinary preparations and fodder supplements on the tasks of the State Committee of Veterinary Medicine of Ukraine during 2010-2018 a number of normative documents were developed regarding procedures related to the use and circulation of feed, feed additives, premixes and veterinary preparations that are composed, containing or made using genetically modified sources in Ukraine: the procedure for state registration, the procedure for carrying out the state veterinary and sanitary examination of GMOs for sources of forage feed additives and veterinary preparations ativ plan state monitoring GMO sources of feed, feed additives, premixes for livestock and poultry. The procedure determines the procedure for state registration of GMOs for sources of feed, feed additives and veterinary preparations containing genetically modified organisms or obtained from their use. It is envisaged that the state register of GMO sources is conducted in the form approved by the State Service of Ukraine for Food Safety and Consumer Protection. On the basis of the analysis, a draft list of feeds, feed materials, protein-vitamin concentrates and premixes that have to be monitored for GMO content has been developed. This project list includes soy, corn, rape and products of their processing, fodder, feed mixes, feed concentrates, etc. In the SSRCI of veterinary drugs and supplements, in 2018, the “Guidelines for identifying the GM soya line (Soybean MON40-3-2) GTS 40-3-2” were developed and approved. “Methodological recommendations are intended to identify the GM soya line (Soybean MON40-3 -2) GTS 40-3-2 (Genetically modified soybean that contains – genetically modified soybean containing (cp4 epsps gene inserted to confer tolerance to herbicide glyphosate) cp4 epsps gene inserted to provide resistance to glyphosate herbicide (glyphosate) in plant material, feed and food products by polymerase chain reaction in real time (PCR-RF )”. The qualitative determination of GMOs is based on the discovery of genetically modified (GM) targeted regulatory sequences of the 35S Cauliflower Mosaic Virus (CaMV) promoter or FMV promoter and/or the NOS (T-NOS) T1 terminator of Agrobacterium tumefaciens plasmids that are introduced into the genetic constructs of GM based on the use of the multiplex polymerase chain reaction method to obtain real-time research results – PCR RF.

A modified SDS-based DNA extraction method from raw soybean.

Soybean is the most important genetically modified (GM) oilseed worldwide. Regulations relating to the approval of biotech soybean varieties and product labeling demand accurate and reliable detection techniques to screen for GM soya. High-quality extracted DNA is essential for DNA-based monitoring methods. Thus, four widely used protocols (SDS, CTAB, DP305, and DNeasy Plant Mini Kit) were compared in the present study to explore the most efficient DNA extraction method for raw soya matrix. The SDS-based method showed the highest applicability. Then crucial factors influencing DNA yield and purity, such as SDS lysis buffer component concentrations and organic compounds used to isolate DNA, were further investigated to improve the DNA obtained from raw soybean seeds, which accounts for the innovation of this work. As a result, lysis buffer (2% SDS (w/v), 150 mM NaCl, 50 mM Tris/HCl, 50 mM EDTA, pH 8.0) and organic reagents including chloroform/isoamyl alcohol (24:1, v/v) (C: I), isopropanol, and ethanol corresponding to the extraction and first and second precipitation procedures, respectively, were used in the optimized SDS method. The optimized method was verified by extracting approximately 2020–2444 ng DNA/mg soybean with A260/280 ratios of 1.862–1.954 from five biotech and non-biotech soybean varieties. Only 0.5 mg of soya was required to obtain enough DNA for PCR amplification using the optimized SDS-based method. These results indicate that the screening protocol in the present study achieves the highest suitability and efficiency for DNA isolation from raw soya seed flour.

Health status and potential uptake of transgenic DNA by Japanese quail fed diets containing genetically modified plant ingredients over 10 generations

The hypothesis assumes that feed containing GMOs affects animal health and results in the transgene product accumulating in the body. Therefore, the objective of the study was to evaluate the impact of genetically modified (GM) ingredients used in poultry diets on aspects of bird health status and accumulation of transgenic DNA in eggs, breast muscle and internal organs.A total of 10 generations of Japanese quail were fed three types of diets: group A – containing GM soya (Roundup Ready) and non-GM maize, group B – containing GM maize (MON810) and non-GM soya, and group C – containing non-GM soya and maize.Bird performance traits were monitored throughout the trial. In 17-week-old animals of each generation, health examination took place on birds from each group including post-mortem necropsy and histological organ evaluation. For the purpose of transgenic DNA detection, samples of selected important tissues were taken. A molecular screening method of PCR amplification was used.The analysis of the sectional examination of birds used in the current experiment did not indicate the existence of the pathological changes caused by pathogens, nutritional factors or of environmental nature. The histopathological changes occurred in all three dietary groups and there were no statistically significant differences between the groups.There was no transgene amplification – neither CaMV35S promoter sequence nor nos terminator sequence, in the samples derived from breast muscle, selected tissues and germinal discs (eggs).According to the obtained results, it was concluded that there was no negative effect of the use of GM soya or maize with regard to bird health status or to the presence of transgenic DNA in the final consumable product.

Genetically modified crops in a 10-generation feeding trial on Japanese quails — Evaluation of its influence on birds’ performance and body composition

The effect of genetically modified (GM) feed components comprising soya bean meal and maize on the performance indices (reproduction, survival rate, growth, egg production, relative weight of chosen internal organs, and basic chemical composition of breast muscle and egg yolk) of Japanese quails was investigated during a 10-generation trial. A total number of 8,438 healthy quail chicks were used in the course of the trial. In each generation, birds were maintained in 3 experimental groups differing in the main feed components, i.e. 1) GM soya (Roundup Ready) and non-GM maize, 2) GM maize (MON810) and non-GM soya, and 3) non-GM soya and maize. The different feeds used did not influence any of the biological hatch indices, survival rate, or BW of young or adult quails. With regard to egg-laying performance, the GM maize group showed a better laying percentage and a higher egg mass production compared to the other groups; the GM soya group showed reduced average egg mass compared to the other groups, whereas the overall egg production level was the same as in the control group. Results showed a higher relative weight of breast muscle and gizzard in birds fed GM maize compared to the control group, whereas live BW and the relative weights of liver and heart were not different among groups. Meat from the GM soya group showed higher protein and lower fat levels compared to the control group. In the case of egg yolk, its chemical composition in the experimental groups did not differ from the control group. Even though some differences were found among the feeding groups, none could be judged as a negative influence of GM maize or GM soya in feed on the birds or final consumer products over 10 generations of Japanese quails.

Quantification of genetically modified soya using strong anion exchange chromatography and time-of-flight mass spectrometry.

Stable-isotope dimethyl labeling was applied to the quantification of genetically modified (GM) soya. The herbicide-resistant gene-related protein 5-enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) was labeled using a dimethyl labeling reagent, formaldehyde-H2 or -D2. The identification and quantification of CP4 EPSPS was performed using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The CP4 EPSPS protein was separated from high abundance proteins using strong anion exchange chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Then, the tryptic peptides from the samples and reference were labeled with formaldehyde-H2 and formaldehyde-D2, respectively. The two labeled pools were mixed and analyzed using MALDI-MS. The data showed a good correlation between the peak ratio of the H- and D-labeled peptides and the GM soya percentages at 0.5, 1, 3, and 5%, with R (2) of 0.99. The labeling reagents are readily available. The labeling experiments and the detection procedures are simple. The approach is useful for the quantification of GM soya at a level as low as 0.5%.

유전자 변이 대두와 옥수수 함유 사료가 참전복(Haliotis discus hannai) 치패의 성장과 체조성에 미치는 영향

Two feeding experiments were conducted to investigate the effects of dietary inclusion of genetically modified (GM) soybean and corn on the growth performance, feed utilization and body composition of juvenile abalone Haliotis discus hannai. Four isonitrogenous (31% crude protein) and isolipidic (6% crude lipid) diets (designated as nGM-soya, GM-soya, nGM-corn and GM-corn) were formulated to contain 20% non-GM (nGM) and GM soya and corn. Fifty juvenile abalone (initial body weight, 2.0 g) were distributed in each 50 L tank in a flow-through system. Each experimental diet was fed to duplicate groups of abalone to satiation once a day for 10 weeks. No effects of GM feedstuffs on survival were observed. Dietary inclusion of GM feedstuffs did not affect either growth performance or feed utilization of abalone. Body composition was not altered by the inclusion of GM feedstuffs. These results indicate that dietary inclusion of GM soybean and corn could have no effect on the growth performance and body composition of juvenile abalone. Further studies to investigate the effects of GM feedstuffs on transgenic fragment residues in ambient environments and in animals are necessary for the safe use of such ingredients in aquaculture.

Refining of Roundup Ready® soya bean oil: Effect on the fatty acid, phytosterol and tocopherol profiles

AbstractIn this study, genetically modified (GM) soya bean seeds with the event known as Roundup Ready® were used for the production of soya bean oil and their fatty acid, phytosterol and tocopherol composition was characterised. Since these compounds can be partially lost during refining, this study also aimed at evaluating the compositional changes along the GM soya bean oil extraction and refining processes carried out industrially. During the refining process of crude soya bean oil, neutralisation was responsible for the major losses on phytosterols (15%). The greatest reduction of tocopherols was also caused by the neutralisation step (20%), while the deodorisation step caused minor losses (9%). Along the refining process, the decreases of total phytosterols and total tocopherols were 20 and 30%, respectively, which are lower than the losses reported in other studies, reflecting the industrial improvements in preserving beneficial health compounds in the refined oil. The results showed that the refined GM soya bean oil presented higher contents of phytosterols (313 mg/100 g) and tocopherols (931 mg/kg) comparing to other reports.

Preliminary Studies on the Effects of Dietary Genetically Modified Soya and Corn on Growth Performance and Body Composition of Juvenile Olive Flounder(Paralichthys olivaceus) and Rockfish (Sebastes schlegeli)

Two feeding experiments were conducted to investigate the effects of dietary genetically modified (GM) soya and com on growth performance, feed utilization and body composition of juvenile olive flounder, Paralichthys olivaceus and rockfish, Sebastes schlegelii. For each fish species, four isonitrogenous (50% crude protein) and isocaloric (4.1 kcal/g) diets (designated as nGM soya, GM soya, nGM com and GM com) were formulated to contain 20% non-GM (nGM) and GM soya and com. Thirty olive flounder (initial body weight, 15.4<TEX>${\pm}$</TEX>0.4 g) and fifty rockfish (initial body weight, 3.1<TEX>${\pm}$</TEX>0.02 g) were distributed in each 400 L tank (200 L water) in a flow through system. Each experimental diet was fed to triplicate groups of fish to visual satiation, twice a day (9:00 hand 17:00 h) for 6 weeks. Growth performance was measured every three weeks. No effects of GM feedstuffs on survival were observed. Dietary inclusion of GM feedstuffs did not affect growth performance and feed utilization of fishes, except for rockfish fed GM com. Rockfish fed the GM com diet showed higher weight gain, daily feed intake and daily protein intake than did fish fed the nGM com diet, but no significant differences were observed in final body weight between the dietary treatments. Condition factor, hepatosomatic index, visceral somatic index and body composition were not altered by the inclusion of GM feedstuffs. These results indicate that dietary inclusion of GM soya and com could have no effects on growth performance and feed utilization of juvenile flounder and rockfish. Lower weight gain and feed intake in flounder and rockfish fed the diets containing 20% soya were likely due to anti-nutritional factors, rather than transgenic factors in the feedstuffs. Dietary inclusion of GM soya and com at the level tested did not alter the body composition of fishes. Further studies to investigate the effects of GM feedstuffs on health conditions and the development of fishes, as well as those of residue of transgenic fragments in ambient environments and in animals are necessary for safe use of the ingredients in aquaculture.

Evaluation of stable isotope labelling strategies for the quantitation of CP4 EPSPS in genetically modified soya

The introduction of genetically modified (GM) crops into the market has raised a general alertness relating to the control and safety of foods. The applicability of protein separation hyphenated to mass spectrometry to identify the bacterial enolpyruvylshikimate-3-phosphate synthase (CP4 EPSPS) protein expressed in GM crops has been previously reported [M.F. Ocana, P.D. Fraser, R.K.P. Patel, J.M. Halket, P.M. Bramley, Rapid Commun. Mass Spectrom. 21 (2007) 319.]. Herein, we investigate the suitability of two strategies that employ heavy stable isotopes, i.e. AQUA and iTRAQ, to quantify different levels of CP4 EPSPS in up to four GM preparations. Both quantification strategies showed potential to determine whether the presence of GM material is above the limits established by the European Union. The AQUA quantification procedure involved protein solubilisation/fractionation and subsequent separation using SDS-PAGE. A segment of the gel in which the protein of interest was located was excised, the stable isotope labeled peptide added at a known concentration and proteolytic digestion initiated. Following recovery of the peptides, on-line separation and detection using LC–MS was carried out. A similar approach was used for the iTRAQ workflow with the exception that proteins were digested in solution and generated tryptic peptides were chemically tagged. Both procedures demonstrated the potential for quantitative detection at 0.5% (w/w) GM soya which is a level below the current European Union's threshold for food-labelling. In this context, a comparison between the two procedures is provided within the present study.

Mass spectrometric detection of CP4 EPSPS in genetically modified soya and maize

The potential of protein fractionation hyphenated to mass spectrometry (MS) to detect and characterize the transgenic protein present in Roundup Ready soya and maize has been investigated. Genetically modified (GM) soya and maize contain the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene from Agrobacterium tumefaciens CP4, which confers resistance to the herbicide glyphosate. The GM soya and maize proteomes were fractionated by gel filtration, anion-exchange chromatography and sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) prior to MS. This facilitated detection of a tryptic peptide map of CP4 EPSPS by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS and nanoelectrospray ionization quadrupole time-of-flight (nanoESI-QTOF) MS. Subsequently, sequence information from the CP4 EPSPS tryptic peptides was obtained by nanoESI-QTOF MS/MS. The identification was accomplished in 0.9% GM soya seeds, which is the current EU threshold for food-labeling requirements.

遺伝子組換えダイズ(ラウンドアップ・レディー・大豆40-3-2系統)の定量検査法の外部精度管理試験

To investigate important factors affecting the analytical results, a laboratory-performance study was attempted for the Japanese official methods to detect genetically modified (GM) soybeans (40-3-2). Test samples containing 0, 1 and 5% GM soya powder in non-GM soya powder was prepared. A set of 3 test samples was sent to the participating laboratories along with the protocol. The data were collected from all laboratories and statistically analyzed. In the real-time PCR detection method, the average values of the GM 1% and 5% samples were both much lower than the spiked value because the laboratories using a silica-membrane DNA extraction method underestimated the GM value. On the other hand, the laboratories using other extraction methods, such as the CTAB method obtained values close to the spiked value. These results suggest that use of the silica-membrane DNA extraction method may result in underestimation of the GM content in the real-time PCR method. In the ELISA method, the average value of 5% spiked samples appears to be slightly higher than the fortified value. But, overall, it was considered that reported values were close to the spiked level.

Characterisation of the 5? integration site and development of an event-specific real-time PCR assay for NK603 maize from a low starting copy number

Genetically modified (GM) maize event NK603 is in the pipeline for authorisation in the EU and is likely to become a dominating GM maize on the world market. The 5′ integration junction was characterised from a small quantity of commercially available genomic DNA. Specific primers and a probe were designed targeting the 5′ integration junction in the plant, amplifying a 102 bp DNA fragment. A method for specific detection and quantification of NK603 using event-specific real-time PCR based on the identified and cloned sequence is described. The assay was specificity tested against five different GM maizes, one non-GM maize and one GM soya bean. Plasmids were constructed for use as external standards in calibration curves. Due to the lack of certified or other suitable commercial reference material for quantification of NK603, the quantifications were performed on non-target DNA spiked with plasmid DNA containing the cloned NK603 5′ integration junction. The plasmid was detectable down to one copy per PCR. The limits of detection (LOD) and quantitation (LOQ) are estimated to be comparable to those of state-of-the-art methods applied for other GM events.

GM food and crops: what went wrong in the UK? Many of the public's concerns have little to do with science.

Genetically modified (GM) crops are now being grown extensively in North and South America and China, although not in Europe. Food produced from these crops has become a part of the normal diet in North and South America and in China, but not in Europe, where contention continues despite the fact that millions of US citizens eat GM soya without any ill effects in a very litigious society, and many Europeans have eaten GM soya while in the US without any adverse consequences. > Why has the British public, who normally so pragmatically welcome scientific advances, resisted the introduction of genetically modified crops? European consumers' continuous and ardent opposition to GM crops and foods has had serious repercussions for plant research, for the commercial development of new crops and, most importantly, for developing countries that could benefit most from GM crops. Several countries in Africa and elsewhere have resisted growing such crops, mainly for fear of being unable to export them to the European market ( The Economist , 2002). It is therefore worthwhile to investigate what actually went wrong in the debate about GM food and crops in Europe and how these foods have earned such a bad name. Such an analysis could not only help to overcome public fears of this technology, but also help scientists and policy makers to address similar concerns in the future, such as the growing debate over nanotechnology. The concerns of European consumers about the potential health and environmental threats of GM crops have resulted in an unprecedented effort to investigate those anxieties and communicate with the wider public, particularly in the UK, where the use of public consultation has been extensively developed. The first of these initiatives was the extensive Farm Scale Evaluations of three GM crops (herbicide‐resistant beet, oil seed rape and maize), whose …

Detection of genetically modified soya in a range of organic and health food products

A selection of organic/health foods containing soya beans was tested for the presence of genetically modified (GM) material. Out of 25 samples of food products containing unrefined soya ingredients, ten tested positively for the presence of GM material. This was surprising because eight out of the ten GM‐positive samples were either labelled as “GM free” and/or were labelled as “organic”, both of which imply the absence of GM ingredients. In no case did any of the foods tested reach the mandatory 1 per cent threshold required for positive labelling as GM products under current European Union legislation, although one product was close to this limit. However, there was considerable batch‐to‐batch variation in the GM soya content of some of the food products, depending on the purchase date and retailer. The paper discusses the implications of these results regarding international regulations on food labelling and use of “GM free” labels or their equivalent.

Analysis and interpretation of data from real-time PCR trace detection methods using quantitation of GM soya as a model system.

Recent years have seen an increased interest in DNA trace detection methods involved in many areas of bioanalytical research, such as quantitation of genetically modified (GM) ingredients in food products. There is little in the way of standardisation of data handling from these methods, and the data generated needs to be analysed appropriately if the results are to be interpreted correctly. This paper describes particular aspects of real-time PCR trace detection methods in order to increase the understanding of data generated using this bioanalytical technique. Using the specific example of GM soya detection and quantitation, it focuses on the production of calibration curves based on the mean and individual data values, the interpretation of correlation coefficients, regression techniques, and discusses suitable data analysis arising from simple and more complex experimental designs following transformation. By using the approaches outlined in this paper, more accurate analysis of data from real-time PCR and GM trace detection methods could be achieved.

Degradation of transgenic DNA from genetically modified soya and maize in human intestinal simulations.

The inclusion of genetically modified (GM) foods in the human diet has caused considerable debate. There is concern that the transfer of plant-derived transgenes to the resident intestinal microflora could have safety implications. For these gene transfer events to occur, the nucleic acid would need to survive passage through the gastrointestinal tract. The aim of the present study was to evaluate the rate at which transgenes, contained within GM soya and maize, are degraded in gastric and small bowel simulations. The data showed that 80 % of the transgene in naked GM soya DNA was degraded in the gastric simulations, while no degradation of the transgenes contained within GM soya and maize were observed in these acidic conditions. In the small intestinal simulations, transgenes in naked soya DNA were degraded at a similar rate to the material in the soya protein. After incubation for 30 min, the transgenes remaining in soya protein and naked DNA were 52 (sem 13.1) % and 34 (sem 17.5) %, respectively, and at the completion of the experiment (3 h) these values were 5 % and 3 %, respectively. In contrast to the soya transgene, the maize nucleic acid was hydrolysed in the small intestinal simulations in a biphasic process in which approximately 85 % was rapidly degraded, while the rest of the DNA was cleaved at a rate similar to that in the soya material. Guar gum and tannic acid, molecules that are known to inhibit digestive enzymes, did not influence the rate of transgene degradation in soya protein. In contrast guar gum reduced the rate of transgene degradation in naked soya DNA in the initial stages, but the polysaccharide did not influence the amount of nucleic acid remaining at the end of the experiment. Tannic acid reduced the rate of DNA degradation throughout the small bowel simulations, with 21 (sem 5.4) % and 2 (sem 1.8) % of the naked soya DNA remaining in the presence and absence of the phenolic acid, respectively. These data indicate that some transgenes in GM foods may survive passage through the small intestine.

Degradation of transgenic DNA from genetically modified soya and maize in human intestinal simulations

The inclusion of genetically modified (GM) foods in the human diet has caused considerable debate. There is concern that the transfer of plant-derived transgenes to the resident intestinal microflora could have safety implications. For these gene transfer events to occur, the nucleic acid would need to survive passage through the gastrointestinal tract. The aim of the present study was to evaluate the rate at which transgenes, contained within GM soya and maize, are degraded in gastric and small bowel simulations. The data showed that 80 % of the transgene in naked GM soya DNA was degraded in the gastric simulations, while no degradation of the transgenes contained within GM soya and maize were observed in these acidic conditions. In the small intestinal simulations, transgenes in naked soya DNA were degraded at a similar rate to the material in the soya protein. After incubation for 30 min, the transgenes remaining in soya protein and naked DNA were 52 (SEM 13·1) % AND 34 (sem 17·5) %, respectively, and at the completion of the experiment (3 h) these values were 5 % and 3 %, respectively. In contrast to the soya transgene, the maize nucleic acid was hydrolysed in the small intestinal simulations in a biphasic process in which approximately 85 % was rapidly degraded, while the rest of the DNA was cleaved at a rate similar to that in the soya material. Guar gum and tannic acid, molecules that are known to inhibit digestive enzymes, did not influence the rate of transgene degradation in soya protein. In contrast guar gum reduced the rate of transgene degradation in naked soya DNA in the initial stages, but the polysaccharide did not influence the amount of nucleic acid remaining at the end of the experiment. Tannic acid reduced the rate of DNA degradation throughout the small bowel simulations, with 21 (sem 5·4) % and 2 (sem 1·8) % of the naked soya DNA remaining in the presence and absence of the phenolic acid, respectively. These data indicate that some transgenes in GM foods may survive passage through the small intestine.

Event-specific detection of Roundup Ready Soya using two different real time PCR detection chemistries

Recently, the DNA sequences of both the 5' and 3' sites of integration of the transgene in Roundup Ready soya have been described. We have utilised this information to design two event-specific assays for the quantitative detection of this genetically modified (GM) organism in food matrices using real time PCR. One assay has been designed to use TaqMan technology for detection using the ABI PRISM 7700 and the second to utilise Scorpion primers for use on the Roche Diagnostics LightCycler detection system. In both cases, the Roundup Ready gene was quantified relative to the endogenous soya lectin gene and results expressed as the percentage of GM soya relative to total soya content using standards of known GM content.

PCR detection of genetically modified soya and maize in foodstuffs.

The detection of genetically modified foodstuffs is becoming both a food sales and legal necessity. This study reports a rapid DNA extraction/PCR-based method for the detection of genetically modified soya (GMS) and maize (GMM) in mixed samples of transgenic and unmodified soybeans and maize kernels, and a variety of processed samples including soya flour, soya protein isolates, extruded defatted soya, acid- and alcohol-precipitated soya concentrates, soya lecithin, maize grits, seasoned corn puffs and salted corn chips. The presence of GMS DNA was determined with two pairs of primers directed towards different GMS target sequences and GMM by one primer pair. In addition, a multiplex PCR reaction which utilises an internal positive control was developed for both genetically modified organisms (GMOs). Results indicated that the methods are sensitive and specific enough to detect GMS down to a level of 0.01% dry weight in single-product PCRs and 0.1% in multiplex PCRs and GMM down to 0.001% dry weight in single-product PCRs and 0.01% in multiplex PCR. The methods are considered to represent a viable route for the commercial detection of GMS and GMM in foodstuffs.