Biotechnology is an archetypal New Economy industry; knowledge-intensive, internationally-oriented, networked in its organisation, and transformative in its effects. There is a substantial sociological literature on biotechnology as a harbinger of new organisational forms. Yet there is widespread uncertainty as to what defines biotechnology in the first place. This paper addresses competing definitions of biotechnology in the Australian context. In doing so, it draws upon Fligstein and McAdam’s concept of 'strategic action fields', which highlights the shifting boundaries of fields, the subjective criteria for their membership, the division between incumbents and challengers, and the importance of framing. In relation to biotechnology, incumbent definitions frame it in terms of scientific techniques, whereas challenger definitions frame it in terms of strategic position in the course of commercialisation. In close connection, challenger definitions are more inclusive and subjective, based on perceptions and reputation. The paper argues that challenger definitions arise partly as a result of convergent scientific techniques in the course of research; partly as a result of the increasingly commercial orientation of scientists; and partly because of the increasing sway of industry actors in the configuration of the field. The upshot is that local biotechnology firms may include only ‘traces of biotech’, but through their strategic action and reputation they are intrinsic elements of the local biotechnology field.