Qualitative and quantitative detection of protein and genetic traits in genetically modified food was discussed. The new approach review, protein and DNA based methods, such as enzyme linked immunosorbent assay, western bolts and qualitative and quantitative polymerase chain reaction. Quantitative GMO detection method measure GMO contents of samples in relation to reference material. It is observed that the rapidly increasing number of GM foods on the markets demand the development or more advanced multidetection systems, such as microarray technologies.