The beginning of the 21st century is characterized by growing interest in the problems of biosafety, which are determined, on the one hand, by the wide use of novel biotechnologies and the necessity to develop the adequate precautionary measures, and, on the other hand, by the objective threat of bioterrorism. Therefore, improvement of the estimation system for genetically modified (GM) sources of food and strengthening the control of their circulation are the urgent problems of modern biology and medicine. Russia is one of the countries where the estimation system of food products obtained from the GM sources is rather efficient. The key features of this system are the complex toxicological and epidemiological examinations. One of the main parts of GM food safety assessment is based upon detection of their potentially toxic properties, which could provoke unintended effects of the genetic modification.