This chapter focuses on ethnographic observations and research interviews with scientists to examine the manifestation of large-scale biological research at a leading UK research centre. It shows that what counts as ‘scale’ and ‘biology’ is ambiguous and fluid by taking a closer look ‘inside’ the laboratories of Big Biology. The Human Genome Project (HGP) was an obvious precursor to -omic large-scale biology, of which contemporary psychiatric genetics is an example. It created a socio-technical apparatus for imagining and organizing biological research on an industrial scale. In psychiatric genetics, the move to Big Biology has produced institutional changes in the individual research sites that operate within an international consortium. The rise of consortium-based collaboration in post-HGP -omic biology is an indication of how large-scale biological research operates across diverse locations and through a variety of material practices. The HGP introduced a socio-technical infrastructure that allowed biological research programmes to re-enter the discovery phase with increased statistical power.