This proposed Technical Specification describes a procedure for the detection of the DNA transition sequence between the 35S promoter region from Cauliflower mosaic virus (P-35S) and the neomycin-phosphotransferase gene (nptII) from the Tn5 transposon of Escherichia coli. The P-35S-nptII construct which confers resistance to neomycin/kanamycin antibiotics is frequently found in genetically modified plants. The detection method is based on real-time PCR and can be used for qualitative screening purposes. For identification and quantification of a specific genetically modified plant (event) a follow-up analysis has to be carried out. This part of ISO 21569 is applicable for the analysis of DNA extracted from foodstuffs. It may also be suitable for the analysis of DNA extracted from other products such as feedstuffs and seeds. The application of this method requires the extraction of an adequate amount of amplifiable DNA from the relevant matrix.