Between the 1870s and the 1920s, the dye industry was at the center of claims about the productivity of organic chemistry. Dyestuffs were widely represented as the most complex molecules to find commercial application, and positioned at the center of nationalist projects to establish chemical industry, especially in Britain and the United States. By the later twentieth century, the complex of scientific hopes which surrounded dyestuffs had largely disappeared. In Hans-Jörg Rheinberger\'s terms, they had changed from \"epistemic things\" to, at best, \"technical objects,\" and lost their future-bearing status as the lynchpin of organic chemistry. Although developments in dyeing continue, dyestuffs have vacated the scientifically and culturally dynamic position that they once occupied; any restoration of this status would require a radical change in economic and material conditions. This paper considers the senses in which this change of status should be considered as the death of dyestuffs as a scientific object.

This paper uses zone electrophoresis, one of the most frequently used tools in molecular biology, to explore two ideas derived from Hans-Jörg Rheinberger\'s reflections on experiments. First, the constraining role played by technical objects-instrumentation and material conditions-in the production of knowledge or epistemic things. Second, the production of interconnected experimental systems by such technical objects, which results in the unexpected entanglement of research fields and experimental cultures. By the beginning of the 1960s, the inception of zone electrophoresis in laboratories around the world transformed-some say, revolutionized-the study of proteins. Even today, electrophoresis continues to open research venues and questions in biomedicine, molecular biology, human genetics, and in the field of molecular evolution. In my essay, I seek to look at the interconnected lives of zone electrophoresis and address the broader social, and even global context, in which this apparently humble technique became a salient tool in the production of biological knowledge. In so doing, I aim to take the past and present of the history and historiography of experimental systems to the future, where experiments and technologies are interrogated as they are used in different geographies and contexts, including contexts of poverty.