Since the blood is already separated form the cellular components and the plasma, blood typing can be a challenge if the medical technologist does not know the theory. Antigens are membrane proteins on the red blood cells. There are 2 types of antigens namely the A antigen and B antigen. Blood types are according to the antigen present in the red blood cells. Blood type O has no antigens in the red cell surface, blood type A has A antigen, blood type B has B antigen, and blood type AB has both A and B antigens. In identifying the antigen, the researcher should extract the cellular components rather the plasma. The plasma, on the other hand, contains antibodies.
