Thirty-five years after its initial success as a form of technologically-assisted human reproduction, and five million miracle babies later, in vitro fertilization (IVF) has become a routine procedure worldwide. In Biological Relatives, Sarah Franklin explores how IVF’s normalization has changed how both technology and biology are understood. Drawing on anthropology, feminist theory, and science studies, Franklin charts IVF’s evolution from an experimental research technique into a global technological platform used for a wide variety of applications -- from genetic diagnosis and livestock breeding to cloning and stem cell research. She contends that despite its ubiquity, IVF remains a highly paradoxical technology that confirms the relative and contingent nature of biology, while creating new biological relatives. Using IVF as a lens, Franklin presents a bold and lucid thesis linking technologies of gender and sex to reproductive biomedicine, contemporary bio-innovation, and the future of kinship.