Synthetic biology is a newly emerging branch of dual-use technology. It is a combination of biology and different branches of engineering. The aim of this article is to show the main technological methods of synthetic biology and to give specific examples of its use to create new types of biological agents and methods of biological warfare, previously unthinkable and presented only in science fiction. Basic tools and techniques of synthetic biology are: DNA synthesis and DNA sequencing; «chassis», i.e. host system harboring the genetic toolbox for expression of the desired genes, delivered by suitable vectors, of the engineered biological pathway; engineering of transcription systems that do not deplete the resources
of the cell (synthetic promotors and transcription factors); genome modification tools (CRISPR/Cas9 nuclease, zinc finger nucleases, TALE nucleases, meganucleases); computer-aided tools (involved in basic structural design and synthesis; in network design; in prediction of behavior/function/response). Synthetic biology has already demonstrared its capabilities in re-creating known pathogenic viruses and pathogenic bacteria; in making existing pathogenic bacteria and viruses more dangerous for humans; in creating new pathogens; in manufacturing toxic chemicals or biochemicals by exploiting natural and artificial metabolic pathways; in making toxic chemicals and biochemicals via in situ synthesis; in modifying the human microbiome; in modifying the human immune system; in modifying the human genome (through addition, deletion, or modification of genes or through epigenetic changes that modify gene expression and can pass from parent to child during reproduction and thus spread a genetic change through the population over time). The article discusses in detail the possibilities of synthetic biology for the development of new means of biological warfare. The author believes that it is necessary not only to constantly monitor these new dual-use biotechnologies, but also to improve traditional and scientific methods of their monitoring.