ABO Blood Group
Blood group antibodies (A, B, AB, and O) can kill red blood cells that carry the antigen they are directed against. These antibodies are also known as “agglutinins.” The four main groups of red-cell antigens are expressed differently in different cultures around the world. They are the result of genes that are passed down from parent to child. The ABO system’s antigens are the most important in blood transfusions because they are found on all cells in the body, including red blood cells.