Most articles on garage biology and do-it-yourself (DIY) biology – whether academic papers or media reports – highlight its somewhat “immaterial” cultures or ideologies. The issues usually raised include: the ways in which do-it-yourself biology potentially democratizes science and fosters a citizen science (Wolinsky, 2009), that its practitioners are a “creative proof of the hacker principle” (Ledford, 2010: 650), that the field is an illustration of the open source movement, that concerns about control, security and safety need to be addressed (Sawyer, 2011). However, rather than focusing on such relatively abstract cultures, this article focuses on the more materialaspects of do-it-yourself biology: its locations, its equipments, its objects. I thus follow Watson and Shove’s (2005) approach and focus on the tools and materials, rather than the symbolic meanings and effects of, do-it-yourself practices (see also Shove et al., 2007: 41-68). This article presents three sites of DIY practices: a community laboratory in Paris, a private laboratory in Boston and, third, cheap alternatives to scientific equipment, such as the DremelFuge. The argument I am concerned with is that the circulability, the affordability and the mutability of objects play a key role in do-it-yourself biology and, at the same time, that we witness the emergence of a “citizen biotech-economy”.