In recent years, genetically manipulated organisms (GMO) have been developed using gene recombination technology, enabling the cultivation of foods that cannot be produced by conventional breeding methods, such as value-added soybeans and corn. In Japan, 22 commercializable products have been reported. These types of agricultural products already are being cultivated in other countries, chiefly the U.S. and Canada, and their use was first permitted in Japan three years ago. In response to concerns regarding recombinant DNA products, implementation of a new system of product labeling for some products will begin in Japan in April 2001. However, although verification of products containing recombinant DNA is being carried out independently by various agencies, the techniques for this work have not been adequately established. Consequently, there is no official certification or labeling procedure, which give arises an obstacle to the safe and effective use of recombinant DNA products.
Even with labeling indicating that recombinant DNA is not used in a product, products containing recombinant DNA can inequitably be avoided when imported from countries such as the U.S. and Canada. Consequently, there is a need to determine the maximum level of recombinant DNA that a product may contain and still be regarded as a product that does not use recombinant DNA. Also the needed is a means of quantifying recombinant DNA levels in products. Methods that have been reported include the TaqMan chemistry and LightCycler methods, which use probes with bound fluorescent substances and the polymerase chain reaction (PCR), and the ELISA method, which use antibodies specific for proteins produced using transgenes. However, because these methods are currently being used independently by the testing agencies, standardization and assurances of the compatibility and accuracy of the data are needed.
Progress toward the establishment of guidelines concerning recombinant DNA products also is expected in the U.S., Canada, and the European countries. Consequently, Japan, taking the initiative this area, is proposing guidelines and working to enable harmonization with the other countries. Coordination to maintain consistency and conformity is also needed in the area of trade.
Therefore, contract work shall be undertaken to examine the basic conditions detecting recombinant DNA products, quantitative and qualitative tests of parameters such as the proportion of recombinant DNA contained in products, and to establish domestic and international standards for detection systems.
The technology advancement committee and outside contractors shall work with our organization in selecting the products to be studied. The products selected and examined shall be agricultural products that have been reported and recombinant-DNA-containing products for which consumer demand is strong.
Standardization of qualitative tests
PCR is currently widely used to detect recombinant genes. However, the extraction efficiency of DNA is not as high for plant cells and processed-food samples as for animals cells. Consequently, efforts shall be made to establish standard processes for extracting and purifying template DNA used in PCR, and primer DNA for use in PCR will be investigated. The investigation of extraction methods include techniques that use cationic surfactants and ion exchange resins.
The determination of whether or not a product is a GMO deemed depending on whether the target gene is amplified by PCR. The regions for amplification and the appropriate length of amplified DNA shall be investigated, and appropriate primers for this purpose will be designed. In addition, the results of these investigations shall be used in examining the reaction conditions for PCR. Finally, the conditions for GMO detection by electrophoresis (e.g., gel concentration, voltage, and staining methods) will be established.
A method of detecting specific proteins in sample tissues is through the use of antibodies specific for the proteins to be detected. This method will be investigated using ELISA (enzyme-linked immuno sorbent assay) and Western blotting.
Standardization of quantitative tests
SYBR Green, TaqMan, and hybridization probe methods
SYBR Green I concentrations, primer sequences, PCR conditions, and fluorescent probe design will be investigated and standardized.
Present conditions and movement of international specification
Although there is no TC for the biological fields in the ISO, investigations of systems for the detection of recombinant DNA products have already begun in the U.S., France, and Germany.
After careful consideration of a strategy for proposing an international specification, preparations will be made for an ISO/TC 34 proposal in cooperation with the Japanese Standards Association (JSA) in order to achieve the objective of developing the research topic. In addition, as a concurrent part of the research and development, strategic international activities will be expanded in order to propose international standards. The aim of these activities, which will also be undertaken with the cooperation of the JSA, will be to ensure consistency with relevant governmental institutions and organizations concerned with international standardization.
Given the urgency of the current situation in Japan, English translations will be undertaken immediately with the aim international standardization. As soon as possible after the completion of the research and development, we, along with the domestic companies Takara Shuzo Co., Ltd., Toyobo Co., Ltd., Roche Diagnostics KK and Toray Research Center, and the Ministry of International Trade and Industry Product Evaluation Center Inc., will assemble the results, which will be disclosed through their practical application domestically.