Abstract: | The preparation of an antigen of Mycoplasma hyopneumoniae containing selected proteins after treatment with the neutral detergent Tween 20 and purification on Sephadex G25 is described. The antigenic activity and the specificity were determined by means of an enzyme linked immunosorbent assay and compared with that of a whole-cell, SDS-solubilised antigen. The Tween 20 purified antigen showed a comparable activity but a higher specificity. |