Your blood also has what is known as an Rh factor: It either contains a certain protein. If you have type A blood, you cannot receive B blood because your body's anti-B antibodies will fight the B blood's B antigens. Human blood falls into four different blood groups: A, B, AB and O. Antigens are markers on the surface of a. For instance, a person with A blood type will have anti-B antibodies, and a person with B blood type will have anti-A antibodies. If your blood is A positive (A+), it means that your blood contains type-A antigens with the presence of a protein called the rhesus (Rh) factor. Depending on the antigen present, we have A, B, O, or AB blood type. The AB blood type has both A and B antigens, and the O blood type has neither A nor B antigen.īy the time you are six months old, you naturally develop antibodies against the antigens your red blood cells lack. Our red blood cells have proteins called antigens on their surface. The A blood type has only the A antigen and the B blood type has only the B antigen. Learn more about blood types and recommended types of donations. This chart is an average distribution of the blood types in the United States. Your ABO blood type is based on the presence or absence of the A and B antigens on your red blood cells. O-positive (O+) is the most common blood type by average percentage. Each letter refers to a kind of antigen, or protein, on the surface of red blood cells. AB positive is considered the universal recipient, and O negative is considered the universal donor. Human blood is grouped into four types: A, B, AB, and O. Rh test Rh blood type checks for the Rh antigen (also called the Rh factor) on red. There are four main blood types: A, AB, B and O. Serious transfusion reactions are rare today because of blood type tests.