The project is to develop blood based laboratory tests for the diagnosis of bovine tuberculosis (BTB). This is necessary because the tuberculin test, which is the only officially approved test in the EC at present does not detect all cattle infected with Mycobacterium bovis and it is a time-consuming and expensive test. The immune response to Mycobacterium bovis is both cellular and humoral and the development of assays which will detect both of these responses is proposed. Antigens which are specific to Mycobacterium bovis will be identified and produced. This will be achieved by the use of extraction and purification from crude preparations, monoclonal antibody production, production of a cell wall antigen, production of fusion proteins containing multiple Mycobacterium bovis specific epitopes and the purification of glycolipid antigens. The cellular response to Mycobacterium bovis antigens will be detected in a bovine interleukin 2 assay. Methods to prolong the useful life of blood samples for cellular assays will be developed. The humoral response to Mycobacterium bovis antigens will be measured by ELISA using the specific antigens developed during the programme. The anamnestic effect of the injection of tuberculin on antibody production will also be investigated in infected cattle.