Immunoglobulin binding factor of seminal plasma: a secretory product of human prostate

To determine the source of the immunoglobulin binding factor (IBF) in seminal plasma, extracts of testis and accessory male sex organs were prepared and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot. The detection reagents used were human and mouse serum Ig, monoclonal anti-Leu 11b antibodies, and polyclonal rabbit anti-IBF antibodies. Of the tissues examined, only the prostate, including benign hypertrophy and adenocarcinoma, contained IBF. These findings suggest that IBF is a secretory product of the prostate.