Between the 1960s and early 1980s, practitioners of physical anthropology and medicine increasingly regarded population genetics research as a powerful tool both to reconstruct the human past and to secure a healthier future. However, the structuring assumptions and interpretations of this new “molecular” or “genetic” anthropology were, and are, embedded in nationalist understandings of history. This paper examines how the practices and technologies of genetic research in this period, particularly methods of blood sampling, have provided a discursive venue for projecting Middle Eastern national narratives into the distant past. Case studies of research performed in Iran, Turkey, and Israel highlight how genetic anthropologists, physicians, and public health officials have navigated the tensions between civic and ethnic nationalism in three states possessing not only highly diverse populations, but also strong government ideologies promoting a homogenized national identity. These tensions generally emerged at the initial stage of defining a population appropriate for biological study. Depending on the priorities of the researchers, genetic data was gathered through one of two principal approaches: either by conducting targeted field surveys to collect blood directly from socially “isolated” ethnic/religious minorities, or by compiling “random” datasets from patients or donors at state-supported hospitals or blood banks. Drawing on published research reports as well as scientists’ professional correspondence and oral histories, I analyze when, how, and why geneticists in each country favored one approach over the other. Israeli geneticists consistently performed targeted surveys that subdivided the national population into small ethnically- and religiously-defined groups, while their Turkish counterparts generally defined their research subjects only in terms of administrative geography. Meanwhile, across the same time period, Iranian genetics research shifted from an emphasis on administrative populations toward investigations of ethnic, religious, and linguistic minorities. I demonstrate that these varying approaches toward breaking down human populations into genetic units represent the effects of different local political contexts and biological conceptions of the nation. I further argue that these trends reflect not a top-down imposition of state ideology upon scientific research, but rather the particular positionality of Middle Eastern geneticists acting simultaneously as technocratic elites within their own countries and as “native informants” within a Western-dominated global scientific community.