Similar to humans and animals, which adapt their diet or behavior to given environmental conditions, the function and protein composition of single cells also depends on which resources are available in their immediate environment. Using a new approach developed by a research team led by Matthias Mann, Director at the MPI of Biochemistry, it is now possible to analyze this protein composition with a view to the environment of individual cells for the first time. By combining two new methods from the research department, they succeeded in functionally mapping the proteome of single cells with high spatial resolution. The results are published in the journal Nature Methods.