Immunostaining of RBC membrane proteins from erythrocytes of DAA and DR patients. RhD-positive (DCCee) and RhD-negative (dccee) membrane proteins were used as controls. The Rh50 glycoprotein carries an N-linked polylactosylaminyl carbohydrate chain2 and is shown as a band of 45- to 75-kD. Antibodies (see the Materials and Methods) are identified on the left-hand side. Stars indicate nonspecific bands occasionally seen from sample to sample and masked in controls due to high intensity of the Rh-specific band.