Detection of Roundup Ready Soybean by Dot Blot

Abstract

The determination of the presence of the 5-enolpyrumylshikimate-3-phosphate synthase (CP4 EPSPS) protein in Roundup Ready soybean (RRS) using Dot blot was evaluated in comparison with the PCR. Experiments were done at the laboratory of GMO detection, the Department of Agriculture, during May 2011-July 2012. Initially, twenty four samples of RRS were collected, screened and verified for real RRS by PCR. After that one sample of verified RRS was ground and protein was extracted using different buffers in comparison with clean water. A suitable ratio of sample and buffer was also determined. The same lot of twenty four RRS samples were then examined for the presence of CP4 EPSPS by the Dot blot using the suitable buffer and sample: buffer ratio condition and self-made specific antibody. Finally, analysis of RRS by PCR and Dot blot was compared. Detection of twenty four RRS samples by PCR revealed that only 11out of 24 samples (ca 45.3%) were the real Roundup Ready soybean, while detection those by Dot blot showed that 9 out of 24 (ca 37.5%) samples were the real Roundup Ready soybean when extracted by guanidine buffer. This result demonstrated that both PCR and Dot could be complementary. However, sample by sample Dot blot and PCR analysis of the RRS occurred 62.5% inly. This could be due to the nature and protocol of detection method, sample size, heterogeneity and concentration of GM materials.