Summary: With funding from the Howard Hughes Medical Institute, the U.S. National Research Council sponsored an intensive lab course for researchers from Central/Eastern Europe at the Institute of Microbiology, Academy of Sciences of the Czech Republic, in Prague. The course ran from Sunday, September 8, to Sunday, September 22, 2002. The aim of the course was to introduce students to modern molecular tools and their application towards understanding the activities of infectious agents and the host response. The course covered a number of concepts and technologies that are relevant to analysis of host-pathogen interactions. A selected group of experts from Europe and the United States provided lectures and led interactive discussions. The laboratory component of the course involved hands-on application of technologies that can be applied to a wide range of systems of host-pathogen interactions.