Contemporary visual epistemic practices in the biological sciences raise new questions of how to transform an iconic data measurements into images, and how the process of an imaging technique may change the material it is ‘depicting’. This case-oriented study investigates microscopic imagery, which is used by system and synthetic biologists alike. The core argument is developed around the analysis of two recent methods, developed between 2003 and 2006: localization microscopy and photo-induced cell death. Far from functioning merely as illustrations of (...) work done by other means, images can be determined as tools for discovery in their own right and as objects of investigation. Both methods deploy different constellations of intended and unintended interactions between visual appearance and underlying biological materiality. To characterize these new ways of interaction, the article introduces the notions of ‘operational images’ and ‘operational agency’. Despite all their novelty, operational images are still subject to conventions of seeing and depicting: Phenomena emerging with the new method of localization microscopy have to be designed according to image traditions of older, conventional fluorescence microscopy to function properly as devices for communication between physicists and biologists. The article emerged from a laboratory study based on interviews conducted with researchers from the Kirchhoff-Institute for Physics and German Cancer Research Center at Bioquant, Heidelberg, in 2011. (shrink)

The pathogenic microbe came to be a widely acknowledged “scientific fact” by the end of the 19th century. Taking the transfer of bacteriological knowledge to Warsaw as an example, this article contributes to understanding the question of how knowledge of bacteria was stabilized outside of its original place of production. Conceiving bacteriological knowledge as a laboratory practice it describes the techniques of mobilizing the “laboratory network” this practice depended on. The case of the Polish medical student Odo Bujwid transporting Robert (...) Koch’s and Louis Pasteur’s laboratory networks to Warsaw will be analyzed. Bujwid used literary and visual inscriptions to make these laboratory networks immutably mobile in Bruno Latour’s sense. But he also had to transport three-dimensional objects central to the networks’ functioning back to Warsaw. Personal exchange was, furthermore, essential to their successful transportation to the Polish kingdom. Next to Bujwid’s efforts to transform the laboratory networks into immutable mobiles, the analysis will extend the focus to mutable mobiles as well and will thus show that the successful stabilization of bacteriological knowledge in Warsaw was due not only to the immutability of its laboratory network but to its flexibility and elasticity as well. (shrink)

: This article analyzes German debates on the microbiology of infectious diseases from 1865 to 1875 and asks how and when organic pollution in tissues became noteworthy for aetiology and pathogenesis. It was with Ernst Hallier's pleomorphistic microbiology that the organic character of alien material in tissues came to be regarded as important for pathology. The process that followed saw both vigorous biological critique and a number of medical applications of Hallier's work. Around 1874 contemporaries reached the conclusion that pleomorphous (...) vegetation was most likely of little importance if not accidental in relation to the aetiology of infectious diseases whereas the idea of monomorphous micro-organisms facilitated a causal explanation. It was only then that notions such a pure cultures, bacterial specificity, etc. favored by Ferdinand Julius Cohn and his school became popular in medical circles. (shrink)

Microphotography was one of the earliest applications of photography in science: The first monograph on tissue organization illustrated with microphotographs was published in 1845. In the 1860s, a large number of introductions to scientific microphotography were published by anatomists. They argued that microphotography was a means of documenting the results of microscopic analysis, uncontaminated by the subjectivity of the observer. In the early decades of the 19th century, before the general acceptance of cell theory, such a technique was of special (...) importance, as no criteria were available to distinguish between important and superficial characters in the description of tissue microstructures. Microphotography was praised as the method of choice for documenting the scientific observations of microscopic material. Some of the microphotographic practices described in these early manuals, however, did not conform with the idea of a purely mechanical process of documentation. The authors of these manuals saw photography not as a technique which produced artifacts, but as a complete and reliable substitute for the original preparations. Thus, according to these authors, the artificial world of photography was seen as the actual representation of the microworld. Consequently, they tried to understand the microcosm by analyzing photographs instead of the microscopic preparation themselves. Such attitudes discredited the use of microphotography in the sciences. Consequently, the definitive breakthrough of scientific microphotography was delayed until the 1880s and was largely due to the efforts of Robert Koch, who made microphotography a central tool of bacteriology. (shrink)