This paper argues that a certain way of thinking about the function of the biobank-about what it does and is constructed for as a social institution aimed at 'some good'-can and should play a substantial role in an effective biobanking ethic. It first exemplifies an 'institution shaped gap' in the current field of biobanking ethics. Next the biobank is conceptualized as a social institution that is apt for a certain kind of purposive functional definition such that we know it by what it does and what it is designed to do. This purpose is then characterized further as essentially incorporating the human goods the institution is designed to serve, such that it plays a useful and indispensible role in how it should operate, i.e. in the ethics and governance of biobanking. Finally the ethical scope and limitations of such a theory is clarified by a discussion of some theoretical objections and suggested practical examples of its application.