[Subtyping of GC globulin in human semen stain]

The group-specific component (GC) is an alpha 2 globulin with high genetic polymorphism in serum. There is also a little amount of GC in human semen. Pflug and Potsch-Schneider independently carried out GC subtyping of human semen stain with immobilized pH gradient gel isoelectric focusing (IPGIF) followed by ELISA in 1988. We report a new method there to subtype GC in human semen stains. First, the GC globulin was separated by polyacrylamide gel isoelectric focusing with pH 4.2-4.9 Pharmalyte. Then, it was immunoblotted to cellulose acetate membranes. Finally, the protein bands were shown by ELISA using horseradish peroxidase-linked secondary antibody system. All the 17 semen stains of volunteers were subtyped successfully. This method is easy to learn and convenient for applying in case work.