Watson then went to Copenhagen University in September 1950 for a year of postdoctoral research, first heading to the laboratory of biochemist Herman Kalckar. Kalckar was interested in the enzymatic synthesis of nucleic acids, and he wanted to use phages as an experimental system. Watson wanted to explore the structure of DNA, and his interests did not coincide with Kalckar's. After working part of the year with Kalckar, Watson spent the remainder of his time in Copenhagen conducting experiments with microbial physiologist Ole Maaløe, then a member of the Phage Group.