نمونه متن انگلیسی مقاله
Cultivation and marketing of genetically modified organisms (GMOs) have been unevenly adopted worldwide. To facilitate international trade and to provide information to consumers, labelling requirements have been set up in many countries. Quantitative real-time polymerase chain reaction (qPCR) is currently the method of choice for detection, identification and quantification of GMOs. This has been critically assessed and the requirements for the method performance have been set. Nevertheless, there are challenges that should still be highlighted, such as measuring the quantity and quality of DNA, and determining the qPCR efficiency, possible sequence mismatches, characteristics of taxon-specific genes and appropriate units of measurement, as these remain potential sources of measurement uncertainty. To overcome these problems and to cope with the continuous increase in the number and variety of GMOs, new approaches are needed. Statistical strategies of quantification have already been proposed and expanded with the development of digital PCR. The first attempts have been made to use new generation sequencing also for quantitative purposes, although accurate quantification of the contents of GMOs using this technology is still a challenge for the future, and especially for mixed samples. New approaches are needed also for the quantification of stacks, and for potential quantification of organisms produced by new plant breeding techniques.
Genetically modified organisms (GMOs) are organisms in which the genetic material has been altered through the application of gene technology in a way that does not occur naturally through mating and/or natural recombination. A GMO is formed by the insertion of one or more functional genes (e.g. the association of two or more DNA sequences arising from different species) into the genome of an organism. This technique is used to produce new genetic combinations (events) that are of value to science, medicine, agriculture and industry, and it has been used with several species of plants, animals, fungi and microorganisms. At present, GM plants are the most important GMOs globally. According to a recent International Service for the Acquisition of Agribiotech Applications report , since 1994, 35 countries and the European Union (i.e. a further 27 countries) have granted regulatory approval for GMOs for food and/or feed use, and for environmental release or planting. A total of 2,833 regulatory approvals involving 27 GM crops and 336 GM events have been issued by the competent authorities .