Produced by the National Institute of Allergy and Infectious Diseases (NIAID), this photomicrographic montage was created by combining two slides, processed using the immunofluorescent antibody technique (IFA). One slide was used to identify spirochetes that express outer surface protein D, resulting in yellow, and red-colored organisms. Again, using IFA on the second slide, spirochetes were labeled with an anti-B. burgdorferi antibody, producing organisms that had stained a glowing green color. The Lyme disease spirochete, B. burgdorferi, is an obligate parasite that cycles between ticks and vertebrate hosts. B. burgdorferi alters the proteins expressed on its outer surface, depending on the state of each host. Therefore, by using two different specimens, and staining the specimens in accordance with these two protein coat configurations, both states are combined into a single image.