Immunonephelometry of specific proteins in human seminal plasma

Using immunonephelometry, we measured albumin, transferrin, alpha 1-antitrypsin, orosomucoid, hemopexin, IgG, IgA, and secretory IgA in seminal plasma of men who were attending a fertility clinic. Seminal plasma, obtained by centrifugation of semen, is a turbid liquid producing high blank values that were not diminished by ultracentrifugation, filtration, or treatment with protamine, dextran sulfate, or various lipidophilic gels. Pretreatment of seminal plasma with polyethylene glycol 6000 (final concentration, 40 g/L) considerably decreased the blank values without appreciably changing the relative concentration of the eight proteins studied. Our investigations illustrate the feasibility of this application of immunonephelometry. This approach can be a valuable diagnostic tool in the laboratory evaluation of the male partner in infertile unions.