This essay argues that the racialized geopolitics of the rhesus monkey trade conditioned the trajectory of tissue culture in polio research. Rhesus monkeys from north India were important experimental organisms in the American “war against polio” between the 1930s and 1950s. During this period, the National Foundation for Infantile Paralysis expended considerable effort to secure the nonhuman primate for researchers’ changing experimental agendas. The NFIP drew on transnational networks to export hundreds of thousands of rhesus monkeys from colonial and later (...) postcolonial India amid the geopolitical upheavals of World War II, the 1947 Partition, and the Cold War. In this essay, I trace how NFIP officials’ anxieties about the geopolitics of the monkey trade configured research imperatives in the war against polio. I show how their anxieties more specifically shaped investment in tissue culture techniques as a possible means of obviating dependence on the market in monkeys. I do so by offering a genealogy of the contingent convergence between the use of rhesus monkeys and HeLa cell cultures in the 1954 Salk vaccine trial evaluation. Through this genealogy, I emphasize the geopolitical dimensions of the search for the “right” experimental organisms, tissues, and cells for the “job” of scientific research. The technical transformation of polio research, I argue, relied on the convergence of disparate, racialized biomedical economies. (shrink)