Up to now, hundreds of GMOs detection methods have been developed, and their number is increasing more and more rapidly.
This is a new research hotspot in the field of GMO detection, and this will greatly facilitate the utilization of PCR detection methods. Moreover, to overcome the difficulties in obtaining the certified reference materials (CRMs) of GMOs, standard reference molecules are developed and used in PCR detection. The introduced DNA fragments are usually integrated into the genome of GMOs by random transformation events: based on the different amplification fragments of the inserted DNA sequences, PCR detection methods of GMOs are grouped into four types, such as the screen-, gene-, construct-, and event-specific PCR methods. Among these techniques, PCR is the most popular technique for GMOs analysis because of its versatility (from screening to identification), specificity, high throughput, and efficiency, therefore the PCR detection methods have been developed for many GMOs.
To make sure the successful enforcement of the GMO labelling, protein and nucleic acid-based detection techniques have been developed, or are in the process of development, such as ELISA, lateral flow strip, PCR, and micro-array etc. In China, no matter how small the GM content is, 17 types of GM products must be labelled, such as maize seeds, maize oil, tomato seeds, ketchup, soybean seeds, soybean oil, rapeseed seeds, and cotton seeds. To protect the consumers' freedom of choice, more than 40 countries have issued GMO labelling regulations, for instance, GM foods must be labelled at the threshold of 0.9% in European Union (EU), 3% in Korea, and 5% in Japan. However, GMOs' emergence has caused public debate on the consumers' freedom of choice to purchase GMO-derived products or not. With the development of modern biotechnology, numerous genetically modified organisms (GMOs) have been approved for commercialization.