Starting from an assessment of how far Robert Koch's bacteriology had developed in the late 1880s this paper attempts to analyse different aspects of the process that led to the foundation of the Berlin Institute for Infectious Diseases in 1891. With the development of his supposed cure against tuberculosis, tuberculin, Koch attempted to give his research a new direction, earn a fortune with the profits and become more independent of Prussian government officials who, up to that point, had had a (...) major influence on his career. In the period following the presentation of the cure in autumn 1890, however, it became clear that tuberculin's value in treatment was at most dubious. Thus, the failure of tuberculin meant that Koch had to drop his own plans and accommodate those of the Prussian Ministry of Culture. As a result he assumed directorship of the newly founded Institute for Infectious Diseases in Berlin. Even though this was definitely a prestigious position it reaffirmed Koch's dependency on Prussian government officials and was by no means the kind of institution he had aimed for at the outset. (shrink)