When HIV/AIDS became a pandemic, epidemiologists wanted to know where it began. In the 1980s, they found their answer in a freezer filled with blood. This blood had been collected in the 1950s from members of indigenous communities in Africa as part of anthropological research on human variation. To this day, that sample is the oldest trace of HIV known to biomedicine. It is what launched Joanna Radin’s interest in the field of biobanking, a means of preserving blood and other tissues for future research.