Unfolding epidemiological stories: how the WHO made frozen blood into a flexible resource for the future.

In the decades after World War II, the World Health Organization (WHO) played an important role in managing the process of stabilizing collections of variable blood samples as a fundamentally unstable, protean, and unfolding biomedical resource. In this system, known and as yet unknown constituents of blood were positioned as relevant to the work of multiple constituencies including human population geneticists, physical anthropologists, and immunologists. To facilitate serving these and other constituencies, it was crucial to standardize practices of collecting and preserving samples of blood from globally distributed human populations. The WHO achieved this by linking its administrative infrastructure-comprised of expert advisory groups and technical reports-to key laboratories, which served as sites for demonstrating and also for disseminating standards for working with variable blood samples. The practices that were articulated in making blood samples into a flexible resource contributes to emerging histories of global health that highlight the centrality of new institutions, like the WHO, new forms of expertise, like population genetics and serological epidemiology, and new kinds of research materials, like frozen blood.