Blood antigens are actually surface proteins found embedded on the red blood cell membrane. The blood type determines the surface antigen and the plasma antibodies found in the blood. If a person is type AB Rh negative, then the person has both A and B antigens on the red cell membrane but without the Rh antigen. On the other hand, the same person has no anti-A or anti-B antibodies in the plasma but has anti-Rh antibodies.
