To be able to examine the function of individual cells or structures in intact tissue, these need to be visible. This may sound trivial, but it is not. To achieve this, researchers implant fluorescent proteins into cells. These will then produce the proteins themselves, without the cell functions being disturbed: cells, structures or their activities thus become visible under the microscope. However, the proteins need to be optimized for their use in research. The required “protein engineering”, in which highly sensitive and specific proteins are developed, is a dedicated research branch. Scientists from the Max Planck Institute of Neurobiology in Martinsried have now developed a method that provides for a significant improvement of protein engineering, by means of automated computer analysis and a robot-supported selection process. This has been verified by first successes achieved with a deep red protein.