Book excerpt: In 1901 Emil von Behring received the first Nobel Prize in med. for serum therapy against diphtheria, a disease that killed thousands of infants annually. Diphtheria serum was the first major cure of the bacteriological era and its develop. generated procedures for testing, standardizing, and regulating drugs. Emphasizes Behring's contrib. to the study of infectious disease, the formation of modern immunology, and research on remedies and vaccines against microbial infections. Explores his relations to the rival bacteriological schools of Robert Koch and Louis Pasteur, the emergent German pharmaceutical industry, and the institutionalization of experimental therapeutic research. Also contains translations of 13 key articles by Behring and his assoc.