Against the background of great expectations associated with the application of big data and artificial intelligence in medicine, various voices have claimed that individuals have a moral obligation to make their data and tissue available for research. This obligation is not only associated with the amounts of materials required in contemporary medical science, but also with presumptions that the knowledge produced in science is a public good. This book critically examines this claim by drawing on four case studies of medical data and tissue collections: the Framingham Heart Study in the United States; the Singapore Tissue Network; the Million Death Study in India; and the European network of sample and data collections BBMRI-ERIC. Each case study is presented as an exemplar for how infrastructures for the purpose of collecting, storing and using population data for medical research are constructed and frame particular versions of ‘collective goods’ in contemporary medical research. While each of these cases is situated in different geographic locations and largely distinct areas of medical research, they jointly illustrate how the making and operations of medical research collections produce particular ‘collectives’ and ‘goods’. This book discusses the making of such collective goods in terms of citizenship to interrogate how the framing of medical research collections generates forms of knowledge that already attribute certain (health-related) rights and responsibilities to different groups of people.