European Respiratory Journal

screening deoxyribonucleic acid (DNA) libraries with immune sera or with immune T-lymphocytes [10, 11]. This study was designed to evaluate diagnostic sensi-tivity and specificity of a novel tuberculosis complex-specific recombinant protein of 34 kDa [12, 13]. An enzyme linked immunosorbent assay (ELISA) test using a fusion protein (MS2-34) comprising the 16 kDa NH2-terminal fragment of the 34 kDa protein and an 11 kDa fragment of the MS-2 polymerase fusion partner indicated elevated anti-34 kDa antibody levels in the sera of patients with TB. By combining this test with an ELISA using the M. tuberculosis-specific recombinant 38 kDa protein (p38) [14, 15], it was possible to diagnose TB in AFB smearnegative patients with high sensitivity and specificity. Methods Production of the recombinant MS2-34 fusion protein Partial expression of the 34 kDa antigen gene [16] was obtained as a 27 kDa fusion protein [17]. Briefly,