Scientific representations include a diverse and confusing array of maps, descriptions, diagrams, and protocols. This study examines and compares the practical and communicative uses of such artifacts. The main source of material is the authors' ethnographic research on the polymerase chain reaction (PCR), a laboratory routine that has numerous scientific, medical, and forensic applications. Contextually relative versions of PCR are examined: schematic diagrams for popular audiences, advertisements in biotech publications, patent descriptions, praxiological descriptions (recipe-like formulations), and material standards and references. These renderings do not exemplify a single type of cognition or information processing. Schematic diagrams, advertisements, patents, protocols, and material standards are differently formed, and the information they convey substantially differs from one form to another. This study contributes to a noncognitivist understanding of representation that emphasizes a plurality of material formats and communicative practices rather than an underlying mental process.