Synthetic biology endeavours to equip biological systems with novel characteristics which are not present in nature and then to put these new characteristics to use. In addition to the new scientific and economic possibilities that can result from this type of undertaking, there are many challenges associated with it. Until now, the required genetic circuits – a combination of genes and the accompanying regulatory units – could only be generated through laborious trial-and-error procedures. The LOEWE research cluster CompuGene aims to reduce the effort required for this step through a close linking of the engineering and the natural sciences. After collecting raw data on the functioning of the biological molecule, its regulators and their interactions, circuit models will be modelled and designed on the computer using engineering principles. Following this, they can then be examined and adjusted in the laboratory. The new functional units should find uses in medicine, biotechnology and biocomputing.