Consumer concern about raw materials and processed products from genetically modified plants and animals (GMOs), especially products processed from soybean and maize, has grown. The development of agriculturally useful genes, such as disease- and insect-resistance genes and herbicide-tolerance genes, has triggered opposition based on biosafety requirements in Thailand and abroad. This led to measures for shipping agricultural products to the European Union and Japan from April 2000, requiring them to state whether they are GMO products.
Standards and requirements
GMO testing follows the same standards as testing in Europe. It reports whether GMO adulteration is present or absent, and can quantify Roundup Ready Soybean. A system has also been developed to prevent the carry-over effect, which causes false positives.
A modified gene has three key parts: 1. the transgene, 2. the promoter and 3. the terminator. These indicate whether raw material fragments and processed products are adulterated with GMOs. There are also selectable and reporter genes, such as NPTII, HPT and GUS, which show which cells received the transferred gene.
Steps for testing fragments, raw materials and processed products from genetically modified plants:
1. Extract DNA from the fragments, raw materials or processed plant products using a suitable method.
2. Analyse the sample DNA by real-time PCR:
2.1 DNA screening: soybean (Lectin gene), maize (Zein gene), plants (18S rRNA gene)
2.2 GMO screening: 35S CaMV promoter, NOS terminator
2.3 GMO identification: RRS (Roundup Ready Soybean)