• Applied Biological Chemistry
• /
• v.48 no.1
• /
• pp.77-81
• /
• 2005

To monitor GM soybean in soybean processed foods, tofu and biji, we prepared tofu and biji containing 0%, 1%, 3%, 5% and 100% GM soybean, respectively. We examined epsps gene inserted in soybean by PCR and EPSPS protein expressed in soybean using western blotting and lateral flow strip test to compare the sensitivity of these methods. A PCR product of 123 bp inserted in GM soybean was detected in all tofu and biji containing 1%, 3%, 5% and 100% GM soybean with the exception of 0% samples; however, the size of 600 bp inserted in GM soybean was only detected in tofu containing 100% soybean and in biji containing 5% and 100% soybean. In the protein level, GM soybean product was only detected in tofu and biji containing 100% GM soybean by western blotting. In addition, only biji containing 100% GM soybean was detected by lateral flow strip test. We concluded that in order to detect GM soybean efficiently in processed food, the PCR method is more sensitive than immunological methods. With the PCR method, small size product with approximately 100 bp in PCR product is sensitive to detect GM soybean in processed foods.