The Microorganism and Arthritis Interaction Laboratory studies an infectious disease transmitted by the bite of ticks called Lyme-like Disease or Baggio-Yoshinari Syndrome. This disease has skin, joint, neurological and cardiac involvement. The disease is diagnosed considering the clinical manifestations, the epidemiology and serological analysis against the etiological agent of the disease. Thus, the laboratory developed and standardized immunological assays for the detection of IgG- and IgM-class immunoglobulins and currently conducts ELISA (Enzyme Linked Immunosorbent Assay) and Western Blotting for the entire HCFMUSP complex, as well as for university hospitals, institutes and central laboratories throughout Brazil. The Microorganism and Arthritis Interaction Laboratory develops research in the area of Molecular Biology in order to identify species of bacteria (Borrelia sp) involved in the etiology of the disease in biological material from humans, domestic and wild animals, and ticks with the collaboration of veterinarians and biologists. Bacteriological and biotechnical research is currently underway in collaboration with Butantan Institute, the main goal of which is to improve laboratory diagnosis of the disease to assist clinical practice. This project is called “Improvement of the serological testing and physiological characterization of the Baggio-Yoshinari Syndrome (Lyme-like disease) as a way to assist diagnosis” and has robust funding from FAPESP. The laboratory makes equipment, supplies and knowledge in the areas of microbiology, immunology and molecular biology available to undergraduate and graduate students.