Study Of Analytical Techniques For Detection Of Genetically Modified Organisms In Crops And Plant-derived Foodstuffs

Genetically modified organisms (GMO) are referred as living organisms of crop origin in which the artificial introduction of foreign genes is able to confer novel characteristics not found in the wild variety. Over the last years, there has been a dramatic and continuing increase of genetically modified crops. More and more trait genes have been introduced into kinds of variety. The figure and complexity of GMO increase constantly. Besides, agricultural products occupy very heavy proportion among our foreign trade; more and more import GMO enters our country already, and our non-GM agricultural product need to export urgently.As model of application of innovative DMA biotechnology in the field of food science, GMO represent a source of hope but at the same time, of concern for their potential implications for the environment and for public health. At present, there isn't an acknowledged GMO international standard yet, there are no unified method and standard for detection of GMO in our country either. So developing GMO analytical techniques as soon as possible would constitute a precious tool for the safety assessment on GMO. They are also the important guarantees for the development of international trade in agricultural products. In this paper, GMO detecting techniques for crops and plant-derived foodstuffs were researched. The available methods for qualitative screening, identification analysis, and quantitative detection of GMO were developed and established. We are trying to offer the basis for the foundation of fast, high-efficient and accurate GMO detecting standard method through this study.Through the methods of biology informatics, we get main information of field-tested and commercialized genetically modified crops from different approach. According to the sequences of 9 foreign genes that have been used in GMO frequently, we designed corresponding primers and probes. These primers and probes were verified to be suitable for practical detecting of GMO.Based on the study of DNA isolation from different samples, this paper applied polymerase chain reaction (PCR) and PCR-derived technology, and utilized many kinds of known samples and reference materials (such as soybean, maize, rice, potato, and pimiento, etc.) to establish the qualitative, half-quantitative, and quantitative GMO detection method:1. We established a qualitative PCR screening method for CaMV 35Spromoter and Tnos terminator. It must be taken into account that false positive results from screening method. So we established restriction endonuclease analysis method (Xmn I for CaMV 35S, Nsi I for Tnos) to verify the amplified positive results. Surface plasmon resonance biosensor method for identification of GMO is presented for the first time. The sensing principle is based on the affinity interaction between nucleic acids: the probe is immobilized on Biacore sensor chips and the target DMA is free in solution. The biosensor method offers a new approach for realizing the automation of GMO detection.2. To improve detection efficiency and result accuracy, we developed an improved multiplex PCR technique for specific detection of GMO. ㏕he assay strategy involves multiplex PCR amplification of the target with several biotinylated primer pairs in one tube, followed by the hybridization of multiplex PCR products and membrane-bound oligonucleotide probes. The multiplex PCR/probe hybrid is detected colorimetrically using an alkaline phosphatase conjugate and a chromogenic substrate. This novel multiplex polymerase chain reaction/membrane hybridization assay (MPCR-MHA) improves detection efficiency obviously, reduces false negative or false positive results, and improves the result accuracy of GMOs detection effectively. ㏕he selected 16 oligonucleotide probes to screen GMO were immobilized in a specific treatment chip by Pixsys?5500. The target sequences were amplified and labeled with Cy3-dCTP fluorescent dye by multiplex PCR. After hybridization of target DNA with low-density gene chip, the microchips...