Current status and detection of genetically modified organism
Tzu‐Ming Pan
Abstract
Production of genetically modified (GM) crops is currently concentrated in just a few countries. In 2001, 99% of GM crops was produced in four countries: US 68%, Argentina 11.8%, Canada 6% and China 3%. Crop-wise, GM soybean made up 63% of global GM planting area and GM corn accounts for 19%, followed by GM cotton (13%) and GM canola (5%). In terms of the global planting area, GM soybean and cotton accounted for 46% and 20%, respectively. Two major genetically modified organisms (GMO) traits in 2001 were herbicide tolerant crops, accounted for 77% of all GM crops, while Bt maize accounted for 11%. Legislation enacted worldwide to regulate the presence of GMOs in crops, foods and ingredients, necessitated the development of reliable and sensitive methods for GMO detection. In this article, protein-, and DNA-based methods employing western blots, enzyme-linked immunosorbant assay, lateral flow strips, Southern blots, qualitative-, quantitative-, real-time- and limiting dilution-PCR methods, are discussed. Where information on modified gene sequences is not available, new approaches, such as near-infrared spectrometry, might tackle the problem of detection of non-approved genetically modified (GM) foods. The efficiency of screening, identification and confirmation strategies should be examined with respect to false-positive rates, disappearance of marker genes, increased use of specific regulator sequences and the increasing number of GM foods.