Bovine purified protein derivative (bPPD) and avian purified protein derivative (aPPD) arewidely used forbovine tuberculosis diagnosis. However, little is known about their qualitative and quantitative characteristics, which makes their standardisation difficult. In addition, bPPDcan give false-positive tuberculosis results because of sequence homologybetween Mycobacterium bovis andM. avium proteins. Here we used proteomics to characterisebPPD, aPPD and an immunopurifiedsubcomplexfrombPPD called P22.