Gerbich-negative red cells lack β and γ sialoglycoproteins (SGPs), which are now known to carry the Gerbich (Ge) antigens. Gerbich and Yus-type Ge-negative red cells possess distinct diffuse SGPs that migrate on sodium dodecyl sulphate polyacrylamide gel electrophoresis in a position between those normally occupied by β and γ SGPs. Both these SGPs lack Ge2 antigens and possess epitopes recognized by monoclonal anti-β. These SGPs differ from each other in at least two ways. The SGP associated with the Gerbich type also lacks the Ge3 antigen and is resistant to trypsin treatment. The SGP associated with the Yus type possesses the antigenic determinant recognized by anti-Ge3 and is sensitive to trypsin digestion.
