DNA is the basis of life on earth. The function of DNA is to store all the genetic information an organism needs to develop, function and reproduce. It is essentially a biological instruction manual found in every cell. Biochemists at the University of Münster have now developed a strategy for controlling the biological functions of DNA with the aid of light. This enables researchers to better understand and control the processes that take place in the cell—for example, epigenetics, the key chemical change and regulatory lever in DNA. The results have been published in the journal Angewandte Chemie.