Extending the cDNA Microarray Detection System to Evaluate Genetically Modified Soybean and Traditional Soy Foods
TZY-LI CHEN1, VENKATESH PRASAD1, CHING-HUA LEE1,2, KUANG-HUNG LIN3, LIH-CHING CHIUEH4 AND MING-TSAIR CHAN1*
1. Institute of BioAgricultural Sciences, Academia Sinica, Taipei 115, Taiwan, R.O.C.
2. Graduate Institute of Biotechnology, Chinese Culture University, Taipei 111, Taiwan, R.O.C.
3. Department of Horticulture, Chinese Culture University, Taipei 111, Taiwan, R.O.C.
4. Bureau of Food and Drug Analysis, Department of Health, Executive Yuan, Taipei 115, Taiwan, R.O.C.
(Received: February 5, 2004; Accepted: June 2, 2004)
ABSTRACT
Aggravating controversies of GM (genetically modified) foods on the social, ethical and health aspects have lead to efficient and reliable detection systems to safeguard homogeneity of foods and address legal disputes. Improvising on the existing detection systems, the present investigation demonstrates the advantages of using cDNA microarray as a detection system for GM food. We have extended the study for the detection of genetic modification in commercial GM soybean seeds and in home-made traditional foods derived from these seeds, such as tofu and dried tofu. We looked for common T-DNA regions such as CaMV35S promoter, NOS or 35S terminators, nptII, hph or pat selection marker genes, GUS or GFP marker genes. We also searched for specific traits such as Bt11, T25, CP4EPSPS and four plant internal control genes (invertase, legumin, tubulin, actin gene). Results indicate that our microarray detection system can identify GM soybean seeds as well as processed food made from these seeds, with 100% accuracy. Transformation events identified in the GM soybean seeds were also visible in the processed foods, thereby confirming the accuracy and reproducibility of this procedure to even processed foods. We believe that with more popularity if the cDNA microarray detection
system will soon be implemented as a diagnostic kit.
Key words: genetically modified organisms (GMO), cDNA microarray, soybean