This chapter conceptualizes the emergence of a techno-scientific field (TSF) as a multiscalar and progressive establishment of a new set of epistemic and social rules. Drawing on science and technology studies and field theories, we design an original conceptual framework that allows us to formulate three propositions to characterize the process of emergence of a TSF. We use the emergence of synthetic biology (Synbio) as a `laboratory' to test this framework. Each proposition refers to a determinant dimension in the process of emergence---heterogeneity, hierarchy, and autonomy. First, we claim that heterogeneity (of disciplines, research questions, visions, social norms) is constitutive of the emergence of a new TSF. Second, the population of Synbio researchers is highly stratified; a core group of scientific entrepreneurs (incumbents and challengers) plays an active role in the process of emergence. Third, strategies for the control of external resources are crucial to the structuration of the field, which is mirrored by the prominent role of core-group members as boundary spanners. An original scientometric approach is used to create specific variables that allow us to investigate both network and field structural dynamics bridging qualitative and quantitative approaches.