Beautiful or Dull? Studying Chromosomes under the Microscope

To study chromosomes under the microscope they need to be spread and flattened, fixed and stained. In short, they are highly manipulated dead objects in an artificial milieu. Yet in practitioners’ eyes, chromosomes have become “hypnotically beautiful objects” (Hsu 1979) to which researchers have remained deeply committed. What makes their observation so fascinating and how has this fascination shaped the development of the field? Drawing on the descriptions of chromosome researchers from the mid-1950s to the early 21st century, the paper will distinguish two kinds of emotional responses to microscopic observation: on the one hand, the emotional attachment to intimately known objects observed over a long period of time and, on the other, the excitement over new observations, combined with the effort of documenting the extraordinary evidence and the possibility of its loss. More generally, the paper will consider how the reliance on visual evidence represented the strength but also the weakness of chromosome research, especially in the eyes of molecular biologists who spurned images in favor of mathematical analysis and causal explanations.