which antigen(s) does type ab blood contain?
There are two antigens, A and B. If you have the A antigen on the RBC, then you have type A blood. When B antigen is present, you have type B blood. When both A and B antigens are present, you have type AB blood. When neither are present, you have type O blood. When an antigen is present on the RBC, then the opposite antibody (also called agglutinin) is present in the plasma. For instance, type A blood has anti-type-B antibodies.