Catherine Waldby is an Associate Professor in the Department of Sociology and Social Policy at The University of Sydney, Australia. In this lecture, delivered on November 6, 2009 at Barnard College, Professor Waldby explores the emerging tensions between women's voluntary (public good) donation of reproductive tissues for stem cell research and the increasing resort to transactional forms of tissue procurement, for example egg sharing and egg vending. She locates this tension in both a feminist biopolitical analysis and in the broader dynamics of the global bioeconomy.