This thesis purports to make two contributions to understandings of biotechnology. First, it presents a novel framework through which to view biotechnology as a complex series of fundamentally social and politically economic mediations rather than a decontextualised collection of technical and scientific phenomena. Second, the thesis presents a method for analysing contemporary discourses about biotechnology within this framework. The framework presented in the first content chapter of the thesis identifies what I see to be the four primary mediating "movements" that are central to seeing Biotechnology as Media: Alienation, Translation, Recontextualisation, and Absorption. The next chapter explicates these movements more fully using a combination of social practice and discourse theory. Using these four movements and the mediation framework as a guide, I then critically analyse a corpus of seventy two exemplary texts (approximately 700,000 words) about contemporary biotechnology. Mediation, in the sense I use it here, is not concerned with one particular media form or technology. Rather, it focuses on the process of mediation as the movement of meanings (Silverstone, 1999). I argue that seeing biotechnologies as mediations can provide a deeper and more critical understanding of how ways of seeing, being, acting, and describing (discourses) associated with contemporary biotechnology are moved from micro- and macro-biological and scientific contexts into the everyday lives of citizens and ecosystems. In particular, such a view highlights the forces and voices that currently determine the path and substance of political-economic movements in biotechnology and, consequently, how everyday perceptions of biotechnology are shaped or silenced in processes of mediation. A core assumption of the thesis is that processes of mediation are not neutral. Rather, they are always inherently interpretive, politically economic, and ethically significant. Any mediation involves "filtering" processes via which "content" is transformed into a form that is appropriate for a given medium by persons who have control over the medium, and by the nature of the medium itself. This applies as much in laboratory and scientific contexts as it does in the contexts of mass consumption, whether in newspapers, policy papers, movies (such as Gattaca), or consumer goods. The same is true in the mediation of biotechnology: there are technological and discursive restrictions on what and who can "contribute to" and "come out" of biotechnology and also what is construed as being a valuable and desirable outcome of biotechnology research and development. The three central analysis chapters of the thesis outline firstly how biotechnology can function as a time-based medium for the reproduction of already powerful discourses on, for example, the role of technology in human development and the consumer market as the moral medium between generators of new technologies and their "consumers". I identify exemplars of how the history of biotechnology and mediation (movement) is expressed in the corpus. This is followed by a more concentrated analysis of the ethical and social significance of the key "official" mediations presented in the corpus. I focus in particular on how the predominant policy evaluations of biotechnological mediations expressed in state, national, and international policy documents construct a "virtuous cycle" of product development that will ostensibly "deliver the benefits" of biotechnology to all citizens who, in the corpus, are framed predominantly as "consumers". The final chapter of the thesis reflects on the significance of biotechnology at the macro level of social practices and systems. Apart from its direct function as a technical medium for alienating hitherto inalienable aspects of life, such as configurations of DNA, and turning them into products for sale, I argue that, as a suite of mediating movements, biotechnology has the potential to effectively, and for the most part invisibly, mediate our more general understandings and experiences of ourselves, of other species, and of the world we live in. More specifically, I argue that biotechnological mediations actively, and often forcefully, promote a narrowing of the range of evaluative resources on offer to the general community, and indeed to biotechnologists themselves. Biotechnological mediations can therefore be described as part of a broader movement away from conditions of heteroglossia or dialogue (multi language, multi voice) toward conditions of monologia (one language, one voice). The thesis concludes with an important question: if we can identify these narrowing effects or mediations of biotechnology by using techniques such as Critical Discourse Analysis and by seeing biotechnology in a mediation framework, what can we do to interrupt them and generate movements that are more generative of heteroglossic and socially responsive ways of seeing, being, and acting? I offer a number of responses to the question in the conclusion.