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On 26 November 2021, the World Health Organization (WHO) classified variant B.1.1.529, reported earlier by the South African authorities as “Variant of Concern” with the name Omicron. The decision was taken because Omicron is bearing a number of mutations with a potential impact on its transmissibility, severity of disease following infection, as well as on the effectiveness of immune protection resulting from both vaccines and natural infection. In this paper, we present an in silico developed RT-PCR based detection method (named OmMet) that was designed to be highly specific for the detection of the Omicron variant. Bioinformatic prediction tests demonstrate that the sequences in the primer sets are highly accurate, and do not match with genetic sequences of other viruses, including other coronaviruses or SARS-CoV-2 variants. The methodology presented does not rely on S-gene target failure (SGTF) of existing RT-PCR assays, widely used currently, but allows the direct specific identification of the variant B.1.1.529 (Omicron).

The digital Polymerase Chain Reaction (dPCR), for the detection and absolute quantification of DNA, is a relatively new technique but its application in analytical laboratories is steadily increasing. In contrast to quantitative real-time PCR, DNA (fragments) can be quantified without the need for standard curves. Using dPCR, the PCR mix containing the (target) DNA is partitioned – depending on the device used – currently into a maximum of 10,000,000 small compartments with a volume as low as a few picoliters. These can be either physically distinct compartments on a chip (referred to as chamber-based digital PCR [cdPCR]), or these compartments correspond to water-in-oil droplets (referred to as droplet digital [ddPCR]). Common to both approaches, once PCR has been carried out simultaneously in all compartments/droplets, the number of positive and negative signals for each partition is counted by fluorescence measurement. With this technique, an absolute quantification of DNA copy numbers can be performed with high precision and trueness, even for very low DNA copy numbers. Furthermore, dPCR is considered less susceptible than qPCR to PCR inhibitory substances that can be co-extracted during DNA extraction from different sources. Digital PCR has already been applied in various fields, for example for the detection and quantification of GMOs, species (animals, plants), human diseases, food viruses and bacteria including pathogens. When establishing dPCR in a laboratory, different aspects have to be considered. These include, but are not limited to, the adjustment of the type of the PCR master mix used, optimised primer and probe concentrations and signal separation of positive and negative compartments. This document addresses these and other aspects and provides recommendations for the transfer of existing real-time PCR methods into a dPCR format., JRC.F.5-Food and Feed Compliance

The recent ruling of the European Court of Justice has confirmed that organisms obtained by mutagenesis techniques are genetically modified organisms (GMOs). However, in contrast to organisms originating from conventional mutagenesis techniques, those obtained by new mutagenesis techniques are not exempted from the obligations of the GMO EU regulatory framework. This ruling raises questions about the detectability of the corresponding GM food and feed products. A case study is used in this document to explain and discuss possibilities and limitations for the detection and quantification of (known and unknown) genetic modifications in plant products derived from new mutagenesis techniques. Many of the mutations induced by new mutagenesis techniques cannot be unequivocally distinguished from natural mutations because such genome editing technologies are able to create very precise and limited genome changes that mimic the result of potential naturally occurring mutations. Moreover, mutations obtained by genome editing technologies could also not be differentiated from those introduced by conventional mutagenesis techniques which have been incorporated in traditional breeding programs and are often not thoroughly documented. Products of genome editing could only be detected and identified in imports of commodity products by enforcement laboratories when prior knowledge on the altered genome sequence, a validated detection method with appropriate selectivity and certified reference materials are available, similarly as required for the authorisation of current transgenic GMOs. However, when the modification involves only a SNP or few nucleotide changes, it would not be possible to identify whether the mutation originated spontaneously or was induced by conventional or new (genome editing) mutagenesis techniques. Moreover, it is unlikely that methods for the quantification of GMO products with small genome modifications in complex food or feed materials provide the level of selectivity needed for the enforcement of legislation, such as the one on labelling. In the absence of prior knowledge on the genome-edited changes, it is likely that non-authorised genetically modified food and feed products obtained by genome editing would enter the EU market undetected. The EU control system for GMOs and corresponding food and feed products may not function as efficiently for unauthorised genome-edited products compared to transgenic GMOs. In particular, the principle of zero tolerance for unauthorised GMO on the EU market is more difficult to maintain., JRC.F.5-Food and Feed Compliance

This report describes the production of a set of Certified Reference Materials (CRMs), ERM 440a, b, c, d and e, which are certified for their DAS-81910-7 cotton (unique identifier DAS-8191Ø-7) event mass fractions. These materials were produced following ISO Guide 34:2009 [1] and are certified in accordance with ISO Guide 35:2006 [2]. Genetically modified (GM) cotton seeds of the DAS-81910-7 event and seeds from a non GM cotton variety were milled to obtain GM and non-GM seed powders with a similar particle size distribution. Mixtures of non-GM and GM cotton seed powder were prepared gravimetrically. The certified values were obtained from the gravimetric preparations, taking into account the water mass fractions of the two powder materials and the genetic purity with respect to the DAS-81910-7 cotton. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements were within the scope of accreditation to ISO/IEC 17025:2005 [3]). The uncertainties of the certified values were estimated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [4] and include uncertainties relating to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of real-time PCR measurements to identify DAS-81910-7 cotton and quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs are available in glass bottles containing at least 1 g of dried cotton seed powder, sealed under an atmosphere of argon. The minimum amount of sample to be used for extraction of the DNA is 200 mg., JRC.F.6-Reference Materials

This report describes the production of a set of Certified Reference Materials (CRMs), ERM BF410ap, bp, cp, dp and ep, which are certified for their GTS 40-3-2 soya bean (unique identifier MON-Ø4Ø32-6) event mass fractions. These materials were produced following ISO Guide 34:2009 and are certified in accordance with ISO Guide 35:2006. The materials are intended for the calibration or quality control of real-time PCR measurements to identify GTS 40-3-2 soya bean and quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs were accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials panel., JRC.F.6-Reference Materials

This report describes the production of a set of Certified Reference Materials (CRMs), ERM-BF412ak, bk, ck, dk and ek, which are certified for their Bt11 maize (unique identifier SYN-BTØ11-1) event mass fractions. These materials were produced following ISO Guide 34:2009 and are certified in accordance with ISO Guide 35:2006. Genetically modified (GM) maize seeds of the Bt11 event and seeds from a non GM maize variety were milled to obtain GM and non-GM seed powders with a similar particle size distribution. Mixtures of non-GM and GM maize seed powder were prepared gravimetrically. The certified values were obtained from the gravimetric preparations, taking into account the water mass fractions of the two powder materials and the genetic purity with respect to the Bt11 maize. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements were within the scope of accreditation to ISO/IEC 17025:2005). The uncertainties of the certified values were estimated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties relating to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of real-time PCR measurements to identify Bt11 maize and quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs are available in glass bottles containing at least 1 g of dried maize seed powder, sealed under an atmosphere of argon. The minimum amount of sample to be used for extraction of the DNA is 200 mg., JRC.F.6-Reference Materials

It is important to guarantee that results expressing the GM content are reliable, comparable and fulfil the requirements of existing EU legislation. The use of different measurement units to express a GM content, the appearance of new analytical methods that do not require a calibrant and the composite EU legislation on GMOs have triggered the need for a document to clarify how to obtain reliable and comparable results. For this guidance document, past and current EU legislations have been reviewed with a special emphasis on what is meant by 'GM percentage' in the different legal texts. The metrological traceability of measurement results and the currently available guidance are explained and summarised. The particular case of botanical impurities and the genetic constitution of GM seeds are described and illustrated to better understand the complexity hidden behind this type of analysis. An overview of the different analytical methods based on DNA measurements and used for the expression of quantitative GM content results is provided, including the use of new techniques based on digital PCR (dPCR). A measuring system that allows for comparing results by making them traceable to the same reference system has been elaborated in detail. Needs and tools are described and a solution has been proposed to convert results expressing GM content to the required measurement unit, whenever this is needed. By following these recommendations, results obtained in GM copy number per haploid genome equivalent (cp/HGE) by dPCR can be converted into mass fraction percentage and compared to the results obtained by quantitative PCR (qPCR) either with a calibrant certified for its GM mass fraction or with a calibrant certified for its GM purity. The general principle is to relate a measurement result to a GM quantity embedded in a specified certified reference material (CRM) either directly or via one single conversion factor (CF) per event. This conversion factor and its related uncertainty need to be determined precisely for each CRM batch, preferably on the pure GM CRM (100 %), using, for example, dPCR. The estimated uncertainty associated with this conversion factor must be integrated into the measurement uncertainty of the final results expressed in GM mass fraction. CF are currently not yet established for most CRMs. CF values have been recently reported in a few pioneer dPCR studies. However, such proof of concept studies remain incomplete. Therefore, to avoid a gap between new technologies and current EU regulation, the working group recommends to launch a dedicated study to determine CF values. Such a study should involve a limited number of competent laboratories with a proven experience in dPCR. The study could be coordinated by the EURL-GMFF., JRC.F.5-Food and Feed Compliance

The European Union Reference Laboratory for Genetically Modified Food and Feed (EURL GMFF) organised a comparative test (CT) for National Reference Laboratories (NRLs) to support the official controls on food and feed in line with Regulation (EC) No 882/2004. Other official control laboratories were allowed to participate on a voluntary basis. Two test items were distributed: a soya milk powder spiked with soybean GM event DAS-444Ø6-6 (Test Item 1, T1) and a maize flour containing maize event VCO-Ø1981-5 (Test Item 2, T2). Participants were required to screen T1 and T2 for the presence of three GM soybean events and three GM maize events, respectively, and to quantify those events identified. The results had to be reported in GM mass/mass %. Eighty-three participants from 38 countries participated to this CT round, including 55 NRLs, of which 33 are designated in line with Regulation (EC) No 882/2004 (NRL/882) and 22 are nominated in Regulation (EU) No 120/2014 to support the EURL GMFF on method validation (NRL/120). The qualitative results, i.e. the correct identification of the GM events, were evaluated and scored as correct or incorrect. The assigned value for the 44406 soybean mass fraction in the soy milk material was derived as the robust mean of the data provided by NRLs, while for VCO-1981, the certified value was set as the assigned value. z and ζ scores were calculated to assess laboratory performance. The results reported indicate that all NRLs identified the correct GM events in both test items and most of the quantitative results were satisfactorily. Five laboratories, including one NRL/882, obtained an unsatisfactory z score for the quantification of 44406 soybean in soya milk powder. All z scores for VCO-1981 maize content in maize flour were satisfactory. A total of 19 and 7 unsatisfactory ζ scores were obtained for events 44406 and VCO-1981, respectively. At least for a number of laboratories this was the due to an underestimation or overestimation of the measurement uncertainty or a failure to report it. A root-cause analysis will be requested from NRLs having reported unsatisfactory results in this CT round and will be followed-up., JRC.F.5-Food and Feed Compliance

This report describes the production of two Certified Reference Materials (CRMs), ERM BF410dn and ERM-BF410gn, which are certified for their GTS 40-3-2 soya bean event mass fractions. These materials were produced following ISO Guide 34:2009 [1] and are certified in accordance with ISO Guide 35:2006 [2]. Genetically modified (GM) seeds of the GTS 40-3-2 soya bean event and seeds from a non-GM soya bean variety were milled to obtain GM and non-GM seed powders with a similar particle size distribution. Mixtures of non-GM and GM soya bean seed powder were prepared gravimetrically. The certified value was obtained from the gravimetric preparations, taking into account the genetic purity with respect to the GTS 40-3-2 soya bean event of the two powder materials and their water mass fractions. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements were within the scope of accreditation to ISO/IEC 17025:2005 [3]). The uncertainties of the certified values were estimated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [4] and include uncertainties relating to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of real-time PCR measurements to identify GTS 40-3-2 soya bean and/or quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs are available in glass bottles containing at least 1 g of dried soya bean seed powder, which were sealed under an atmosphere of argon. The minimum amount of sample to be used for extraction of the DNA is 200 mg. The CRMs were accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the production of a set of Certified Reference Materials (CRMs) ERM BF439a, b, c, d and e, which are certified for their 4114 maize event mass fractions. These materials were produced following ISO Guide 34:2009 and are certified in accordance with ISO Guide 35:2006. The materials are intended for the calibration or quality control of real-time PCR measurements to identify 4114 maize and/or quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs were accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the processing and certification of genomic lambda deoxyribonucleic acid (DNA) in a solution. ERM®-AD442k is certified for its lambda DNA mass, expressed in ng/µL. The DNA copy number concentration in cp/µL is provided as an indicative value. The material was produced according to ISO Guide 34:2009. A volume of approximately 400 mL of lambda DNA at an approximate concentration of 450 ng/µL was purchased from Promega Corporation and Benelux BV (Madison, USA and Leiden, NL). After homogenising and diluting this solution with TE buffer, 3100 vials of ERM-AD442k were produced. Each ERM-AD442k vial contains a certified DNA mass concentration of 57.53 ng/µL with an expanded combined uncertainty of 1.07 ng/µL. Using two different next generation sequencing (NGS) techniques (i.e. an Illumina platform and the GS Junior platform from Roche), the nucleic acid sequence of the lambda DNA in ERM-AD442k was verified. Non-lambda DNA sequences were identified in this material. The relative proportion of those sequences was estimated by NGS and further quantified by quantitative polymerase chain reaction (qPCR). Traces of the contaminating DNA, mainly coming from the Escherichia coli (E. coli) host used by Promega Corporation and Benelux BV to produce the lambda DNA, were negligible. Between-vial homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. Within-vial homogeneity was quantified to determine the minimum sample intake. The certified DNA mass concentration value was obtained by ultraviolet (UV) spectrophotometry and the indicative DNA copy number concentration value by digital PCR (dPCR). The DNA copy number concentration measured by dPCR is consistent with the DNA mass concentration determined by UV spectrophotometry. The measurements were performed according to the scope of accreditation to ISO/IEC 17025:2005. The material was characterised by an inter-laboratory comparison exercise performed by laboratories of demonstrated competence and with adherence to ISO/IEC 17025. Technically invalid results were removed; however no other outliers were eliminated on statistical grounds only. Uncertainties of the certified and indicative values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties relating to possible inhomogeneity and instability, and to characterisation. The material and its certified value are intended to be used for the calibration of DNA quantification methods, quality control and assessment of method performance. As any reference material, it can also be used to establish control charts or in validation studies. The indicative value of the material is, in contrast to the certified value, a value where the uncertainty was deemed too large to allow certification and is therefore less reliable than the certified value. The CRM is available in Axygen maximum recovery polypropylene vial containing a nominal volume of 1.1 mL lambda DNA in solution. The minimum amount of sample to be used is 50 µL for UV spectrophotometry and 68 µL for dPCR. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the production of a set of Certified Reference Materials (CRMs) ERM BF438a, b, c, d and e, which are certified for their VCO-Ø1981-5 mass fractions. These materials were produced following ISO Guide 34:2009 and are certified in accordance with ISO Guide 35:2006. Genetically modified (GM) seeds of the maize event VCO-Ø1981-5 and seeds from a non-GM maize variety were milled to obtain GM and non-GM seed powders with a similar particle size distribution. Mixtures of non-GM and GM maize powder were prepared gravimetrically. The certified value was obtained from the gravimetric preparations, taking into account the genetic purity with respect to the event VCO-Ø1981-5 of the two powder materials and their water mass fractions. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements were within the scope of accreditation to ISO/IEC 17025:2005). The uncertainties of the certified values were estimated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [4] and include uncertainties relating to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of real-time PCR measurements to identify VCO-Ø1981-5 maize and/or quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs are available in glass bottles containing at least 1 g of dried maize seed powder, which were sealed under atmosphere of argon. The minimum amount of sample of the mixtures to be used and recommend for the blank and pure VCO-Ø1981-5 materials is 200 mg. The CRMs were accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the preparation and characterisation of a set of three plasmid solutions, ERM-AD482a, ERM-AD482b and ERM-AD482c. The material was produced in accordance with ISO Guide 34:2009 [1]. A DNA fragment specific for the identification of ruminant meat was cloned into a pUC18 vector to construct the pIRMM-0103 plasmid. The nucleic acid sequence of the entire pIRMM-0103 plasmid was determined by dye terminator cycle sequencing applying the primer walking method on the entire plasmid. The plasmid was put into a solution and its concentration was measured by ultraviolet (UV) spectrophotometry. Afterwards this solution was gravimetrically diluted to obtain three different plasmid concentration levels. The plasmid copy number concentration of the three concentration levels were certified by digital quantitative polymerase chain reaction methods (dPCR). In addition, between-unit homogeneity, as well as short-term long-term and freeze-thaw stability was assessed in accordance with ISO Guide 35:2006 [2]. The materials are intended for the determination of a cut-off value to discriminate positive samples (containing the ruminant target sequence) from negative samples by quantitative PCR as defined in the Standard Operating Procedure of the EU Reference Laboratory for animal proteins (EURL-AP) according to Commission Regulation No 51/2013 [3, 4]. As any certified reference material (CRM), the materials can also be used for control charts or validation studies. The CRM is available as a set of three vials each containing at least 1 mL of plasmid solution. The minimum amount of sample to be used is 4 µL., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the preparation and characterisation of a set of plasmid solutions, ERM-AD483a, ERM-AD483b and ERM-AD483c. The materials were produced in accordance with ISO Guide 34:2009 [1]. A DNA fragment specific for the identification of a porcine target was cloned into a pUC18 vector to construct the pIRMM-0104 plasmid. The nucleic acid sequence of the entire pIRMM-0104 plasmid was determined by dye terminator cycle sequencing. The plasmid was eluted in TElow buffer, and its concentration was measured by ultraviolet (UV) spectrophotometry. Afterwards, it was gravimetrically diluted to three different concentration levels. The plasmid copy number concentration of the three concentration levels were certified by digital and droplet digital quantitative polymerase chain reaction methods, dPCR and ddPCR respectively. In addition, between-unit homogeneity, as well as short-term and long-term stability was assessed in accordance with ISO Guide 35:2006 [2]. The materials are intended for the determination of a cut-off value to discriminate positive samples (containing the porcine target sequence) from negative samples by quantitative PCR as defined in the Standard Operating Procedure of the EU Reference Laboratory for Animal proteins (EURL-AP) according to Commission Regulation (EU) No 51/2013 [3, 4]. As any certified reference material (CRM), ERM-AD483 can also be used for control charts or validation studies. The CRM is available as a set of three vials, each containing at least 1 mL of plasmid solution. The minimum amount of sample to be used is 4 µL., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the production of a set of Certified Reference Materials (CRMs) ERM BF437a, b, c, d and e, which are certified for their DAS-81419-2 mass fractions. This material was produced following ISO Guide 34:2009 and is certified in accordance with ISO Guide 35:2006. Genetically modified (GM) seeds of the soya event DAS-81419-2 and seeds from a non-GM soya variety were milled to obtain GM and non-GM seed powders with a similar particle size distribution. Mixtures of non-GM and GM soya powder were prepared gravimetrically. The certified value was obtained from the gravimetric preparations, taking into account the genetic purity with respect to the event DAS-81419-2 of the two powder materials and their water mass fractions. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements were within the scope of accreditation to ISO/IEC 17025:2005). Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties relating to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of real-time PCR measurements to identify DAS-81419-2 soya and/or quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs are available in glass vials containing at least 1 g of dried soya seed powder which were sealed under atmosphere of argon. The minimum amount of sample to be used is 200 mg. The CRMs were accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium, JRC.D.2-Standards for Innovation and sustainable Development

The content of this manual is based on the training course that was organised on the premises of the European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (Geel, BE) at the end of 2013. The training manual complements the training course that was intended to improve the quality of measurement results obtained when quantifying genetically modified organisms (GMO) in food and feed. Both, the training course and this manual, were developed in line with the current EU GMO legislation. The manual is addressed to laboratory managers and practitioners in analytical laboratories who perform GM quantification measurements and use reference materials for calibration, quality control and method validation including in-house verification. It is also intended for analysts who need to assess measurement uncertainties as required by (EC) No 1829/2003, (EC) No 619/2011 and ISO/IEC 17025:2005. This training document has been written by JRC-IRMM upon request of the European Union Reference Laboratory for Genetically Modified Food and Feed (EURL-GMFF) to further improve the reporting of National Reference Laboratories (NRLs) nominated under Regulation (EC) No 882/2004 and official GMO control laboratories within the EU. This manual is organised in four chapters covering the proper calibration of PCR methods, the estimation of measurement uncertainty, the establishment of metrological traceability of a measurement result and the way to prove the trueness of measurement results. The training manual is a didactic support of a previous guidance document that outlines issues related to the estimation of measurement uncertainty (MU) in the GMO sector. The training manual is also in line with the European technical guidance document for the flexible scope accreditation of laboratories quantifying GMOs, that is intended for laboratories that are acquiring or are holding a flexible scope of accreditation according to ISO/IEC 17025., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the processing of a set of plasmid solutions, IRMM-AD482a, b and c. The material was produced following ISO Guide 34:2009. A DNA fragment specific for the identification of ruminant meat were cloned into a pUC18 vector to construct the pIRMM-0103 plasmid. The plasmid was diluted to three different concentration levels. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The materials are intended for the determination of a cut-off value to discriminate positive samples from negative samples by quantitative PCR. As any reference material, the materials can also be used for control charts or validation studies. The RM is available as a set of three plastic tubes containing 1 mL of plasmid solution. The minimum amount of sample to be used is 4 μL., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the production of the set of Certified Reference Materials (CRMs) ERM-BF434a, b, c, d and e. These are matrix materials certified for their 73496 rapeseed mass fractions. The material has been produced following ISO Guide 34:2009. Genetically modified (GM) rapeseeds of the event 73496 and of a non-GM rapeseed variety were ground to obtain GM and non-GM base powders. Gravimetric mixtures of non-GM and GM rapeseed powder were prepared by dry-mixing. The between unit-heterogeneity has been quantified and stability during dispatch and stability during storage have been assessed in accordance with ISO Guide 35:2006. The certified value was obtained from the gravimetric preparations, taking into account the purity of the base materials and their respective water mass fraction. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements within the scope of accreditation to ISO/IEC 17025:2005). Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of 73496 rapeseed identification and quantification methods. As any reference material, they can also be used for control charts or validation studies. The CRMs are available in glass vials containing at least 1 g of dried rapeseed powder closed under argon atmosphere. The minimum amount of sample to be used is 200 mg. The CRM has been accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium., JRC.D.2-Standards for Innovation and sustainable Development

This report describes the production of a set of Certified Reference Materials (CRMs) ERM BF436a, b, c, d and e, certified for their DAS-44406-6 mass fractions. The material was produced following ISO Guide 34:2009. Genetically modified (GM) seeds of the soya event DAS-44406-6 and of a non-GM soya variety were milled to obtain GM and non-GM powders. Gravimetric mixtures of non-GM and GM soya powder were prepared by dry-mixing. Between-unit homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The certified value was obtained from the gravimetric preparations, taking into account the purity of the base materials and their water mass fraction. The certified values were confirmed by event-specific real-time PCR as independent verification method (measurements within the scope of accreditation to ISO/IEC 17025:2005). Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties related to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of methods. As any reference material, they can be used for establishing control charts or validation studies. The CRMs are available in glass vials containing at least 1 g of dried soya seed powder and closed under argon atmosphere. The minimum amount of sample to be used is 200 mg. The CRMs were accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium., JRC.D.2-Standards for Innovation and sustainable Development

The aim of this guidance document is to facilitate harmonised flexible scope accreditation within Europe, according to ISO/IEC 17025:2005 related to quantitative testing of genetically modified organisms (GMOs) by quantitative real-time polymerase chain reaction (qPCR) for GM events authorised in the EU or which are in the authorisation process. This document gives guidance to and is intended for laboratories that are considering to acquire a flexible scope of accreditation according to ISO/IEC 17025. At the same time it aims to provide information for assessors involved in the accreditation process of these laboratories. This guidance document has been written by members of the Task Force (TF) Flexible scope accreditation, which has been initiated by European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (EC JRC-IRMM, Geel, BE). After an extensive commenting phase it has been submitted to the European co-operation for Accreditation (EA) in February 2013 for consideration as an EA guidance document., JRC.D.2-Standards for Innovation and sustainable Development