Demonstration of organ-characteristic glycoproteins in human semen.

Tridacnin M, a galactosyl-specific reagent prepared from the bivalve clam Tridacna maxima (Röding) was used for the demonstration of 2 different glycosubstances with terminal galactosido units in human semen. The results obtained by immunodiffusion tests indicate that the seminal plasma contains a water-soluble glycoprotein with two carbohydrate chains, one of them having a terminal beta-galatosyl group whereas the other one seems to have a terminal N-acetyl-neuraminic acid group and a subterminal beta-galactosyl group. This glycoprotein is a secretion product of the seminal vesicles and, therefore, of diagnostic significance: it is absent in cases of bilateral occlusion of the ampullae. Another glycosubstance with terminal galactosido-residues could be demonstrated on the surface of sperm cells by agglutination reactions. This glycosubstance is an integral part of the spermatozoan membrane because it cannot be removed by repeated washings.