Padlock probe locations in a GMO and GMO decision tree. Scheme for the location of specific padlock probes on species-, construct-, element- and event level of a GMO. EPS = endogenous plant sequence (A). GMO decision tree in which the outcomes of DNA analyses are matched with the data from a database on known GM crop events to elucidate the presence and status of GMOs in a test sample. Here, events, elements, constructs and species are detected and compared with the database information. Detection of unknown GMOs is by exclusion of profiles of known GMOs present within the sample (B).