Immunoblotting characterization of CA 125 in biological fluids:difference between pregnancy and cancer CA 125 origin.

The CA 125 present in various biological fluids (serum, cyst, peritoneal and amniotic fluids, human milk, seminal plasma, cervical mucus and Wish culture medium), was characterized by gel chromatography and immunoblotting analysis. The elution profile of CA 125 from different sources was closely related. The antigen was eluted primarily in the void volume of a Sephadex G-200 column. Immunoblotting analysis showed that the CA 125 epitopes reside on a high molecular weight species of greater than 900 kDaltons, and are between approximately 900 and 200 kDaltons. The expression of the immunoreactive bands was characteristic for each type of sample was examined. A strong difference was identified between CA 125 from pregnancy and that from ovarian cancer. There differences suggest that the production and/or metabolism of CA 125 glycoprotein might be different from tissue to tissue.