Pneumonic plague is a potentially lethal lung infection caused by a bacterium called Yersinia pestis. Although outbreaks seldom plague developed countries, plague affects thousands of patients in developing nations, primarily in Africa, and it is a worldwide bioterrorism threat. It can be treated with antibiotics if caught early enough, but current diagnostic techniques, such as polymerase chain reaction assays, are complex, expensive, and slow. Plague-specific oligosaccharide antigens from the Y. pestis cell surface can be used to develop immunological tests for plague, but they are difficult to isolate. Now, Chakkumkal Anish, Peter H. Seeberger, and coworkers at the Max Planck Institute of Colloids & Interfaces, in Germany, have sidestepped that problem: They synthesized such an antigen and conjugated it to a protein, identified monoclonal mouse antibodies that bind the conjugate specifically, and used the antibodies to develop an immunoassay that detects plague conveniently and inexpensively (Angew. Chem. Int. Ed. 2013, DOI: 10.1002/anie.201301633). A Swiss defense lab is developing the immunoassay commercially. The work is “a beautiful combination of state-of-the art oligosaccharide synthesis and immunology to address an important health concern,” comments Todd L. Lowary of the University of Alberta.