Current Progress on the Detection of Genetically Modified Organisms in Food: From Transgenic Towards Genome-Edited...

Progresses in biotechnology, particularly the introduction of genetically modified organisms (GMO) and, more recently, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas-mediated genome editing, have revolutionized agriculture, prompting the need for robust food-labeling regulations. To meet the GMO legislation requirements, analytical methods for the reliable detection of GMO in food, based either on DNA or protein markers, have been constantly proposed. DNA-based methods relying on polymerase chain reaction (PCR) technologies are the most popular for this purpose, with real-time PCR being the gold standard for GMO quantification. Lately, digital PCR has proved to be a suitable alternative to real-time PCR. The development of rapid, low-cost, user-friendly, and field-deployable tools to quickly generate data on the presence of GMO is crucial, especially with the rapid increase in their complexity and the number of events entering the food market. In this context, alternative technologies based on isothermal amplification and genosensors have emerged. The immunochemical assays in the formats of microtiter plates, lateral flow devices, and immunosensors still occupy a relevant role in GMO detection. Finally, next generation sequencing technologies stand up as tools to face the challenges of detecting unauthorized GMO and genome-edited crops. This review intends to provide a comprehensive overview on the methodologies available for the detection, identification, and quantification of GMO, including gene-edited mutants in foods, while discussing their advantages and limitations, with focus on the latest advances.